ZYGADS1IUS,    OR   D3ATH    C ALIAS 

By  Marsh.,    Ciawson,   H.   Marsh 

U.S.D.A.    Bui.    #135.  mj  13      1915 


UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 
BULLETIN  No.  125 

Contribution  from  the  Bureau  of  Plant  Industry,  Wm.  A.  Taylor,  Chief, 
and  the  Bureau  of  Animal  Industry,  A.  D.  Melvin,  Chief 


Washington,  D.  C. 


PROFESSIONAL  PAPER 


May  13, 1915 


ZYGADENUS,  OR  DEATH  CAMAS 


By 

C.  DWIGHT  MARSH  and  A.  B.  CLAWSON,  Physiologists 
and  HADLEIGH  MARSH,  Veterinary  Inspector 


CONTENTS 


Page 

Introduction 1 

Description  of  Zygadenus 4 

Common  Names  of  Zygadenus  ...  6 

Poisonous  Species  of  Zygadenus  .  .  6 

Losses  of  Live  Stock  by  Zygadenus  .  .  6 

Animals  Poisoned  by  Zygadenus  ...  7 
Symptoms  Produced  by  Zygadenus 

Poisoning 7 

General  Statement  of  Experimental 

Work 8 

Symptoms  in  Sheep  Observed  at  the 

Greycliff  Station 24 

Symptoms  in  Horses  and  Cattle  .  .  29 

Autopsies 29 


Page 
Toxic  and  Lethal  Dose  of  Zygadenus 

Venenosus  for  Sheep 30 

Experiments  with  Horses  and  Cattle  .  34 
Comparative     Toxicity     of     Different 

Species  of  Zygadenus 35 

Does  Toxicity  Vary  with  Locality    .     .  35 
Effect  of  Repeated  Feeding  in  Produc- 
ing Immunity  or  Increased  Suscepti- 
bility       37 

Remedies ,,     .     .     .  37 

Methods  of  Preventing  Losses      ...  43 

General  Summary 44 

Literature  Cited          45 


WASHINGTON 
GOVERNMENT  PRINTING  OFFICE 

1915 


-  J.YIJUU 


BULLETIN    OF  THE 


No.    125 

Contribution  from  the  Bureau  of  Plant  Industry,  Wm.  A.  Taylor,  Chief 

and  the  Bureau  of  Animal  Industry,  A.  D.  Melvin,  Chief. 

May  13,  1915. 

(PROFESSIONAL  PAPER.) 


ZYGADENUS,  OR  DEATH  CAMAS. 

By  C.  DWIGHT  MARSH  and  A.  B.  CLAWSON,  Physiologists,  Drug-Plant  and  Poisonous- 
Plant  Investigations,  and  HADLEIGH  MARSH,  Veterinary  Inspector,  Bureau  of  Ani- 
mal Industry. 

INTRODUCTION. 

HISTORICAL  SUMMARY  AND  REVIEW  OF  LITERATURE. 

Chesnut  and  Wilcox  (1901,  p.  52) 1  say  that  "the  earlier  explorers 
of  the  Western,  and  especially  of  the  Northwestern,  United  States  fre- 
quently mention  the  poisonous  character  of  the  bulbs  of  one  or  the 
other  of  the  various  species  of  Zygadenus  and  refer  to  them  as  poison 
camas  or  poison  sego  in  order  to  distinguish  them  from  bulbs  of  two 
other  groups  of  plants,  Quamasia  and  Calochortus,  which  were  com- 
monly known  as  camas  and  wild  sego  and  were  much  used  for  food, 
both  by  the  Indians  and  by  travelers.  Accounts  of  the  poisoning 
of  stock  from  eating  the  roots  and  leaves  of  various  species  have  but 
recently  been  sent  to  this  Department. " 

This  statement,  perhaps,  covers  the  knowledge  of  the  subject  up 
to  that  date,  although  the  writers  have  failed  to  find  much  in  the 
way  of  definite  statement  among  the  earlier  writers  that  can  be  re- 
ferred to  this  plant. 

In  Wyeth's  journal  of  his  second  expedition  to  Oregon  (Wyeth, 
1899)  occurs  this  statement: 

16th.  Made  down  the  Sandy  S.  W.  by  W.  15  miles  then  4  S.  E.  by  E.  and  camped 
on  this  stream  so  far  the  grass  is  miserable  and  the  horses  are  starving  and  also  at  last 
night's  camp  they  eat  something  that  has  made  many  of  them  sick  the  same  thing 
happened  two  year  since  on  the  next  creek  west. 

This  happened  on  June  16,  1834,  somewhere  between  Big  Sandy 
Creek  and  Leckie,  in  Fremont  County,  Wyo.  The  present  knowl- 
edge of  the  botany  of  that  region  makes  it  almost  certain  that  the 
poisonous  plant  in  that  place  at  the  time  of  year  mentioned  must 

1  For  the  complete  titles  of  works  cited,  see  the  list  of  literature  on  pages  45  and  46. 

NOTE.— This  paper  is  intended  to  supply  general  information  on  the  relation  of  Zygadenus  to  the  losses 
of  live  stock  on  the  western  stock  ranges;  it  is  suitable  for  distribution  throughout  the  western  third  of 
the  United  States. 

47698°— Bull.  125—15 1 

487711 


OF  AGRICULTURE. 


have  been  Zygadenus.  This  is  the  earliest  reference  to  probable 
poisoning  by  Zygadenus  which  has  been  found  by  the  writers. 

Asa  Gray  (1848)  says  of  Amianthium  nuttallii,  now  known  as 
Zygadenus  nuttallii,  "Crescent  cum  Kamassa  esculenta,  quo  bulbi 
nocentes  viatoribus  saepe  confusi  sunt." 

Hooker  (1838)  says  of  LeimanMum  nutallii,  which  is  the  same  as 
the  species  mentioned  by  Gray,  "  'Poison  or  Death  Camass'  of 
the  Chenooks,  from  the  violent  effects  of  the  roots,  which  create 
vomiting." 

Watson  (1880)  speaks  of  Zygadenus  venenosus  as  poisonous  and 
known  to  the  Indians  as  "Death-Camass,"  and  says,  on  page  184,  that 
the  bulb  of  Z.  paniculatus  is  also  poisonous. 

Apparently  the  Lloyds  (1887)  were  the  first  to  state  definitely  the 
symptoms  produced  by  the  plant  in  human  beings. 

Irish  (1889)  fed  "cammers"  to  steers  without  effect. 

Hillman  (1893)  published  a  newspaper  bulletin  calling  attention 
to  the  poisonous  character  of  Zygadenus,  and  in  1897  he  published 
another  newspaper  bulletin  on  the  same  subject.  Also,  in  another 
publication  (1897&,  p.  115),  lie  states  that  a  horse  is  reported  to 
have  been  made  sick  by  the  seeds  of  Zygadenus  paniculatus  in  hay. 

Coville  (1897)  says  that  Zygadenus  venenosus  causes  extreme  vomit- 
ing and  that  it  is  sometimes  used  by  medicine  men  of  the  Klamath 
Indians,  mixed  with  the  dried  roots  of  Iris  missouriensis  and  a  little 
tobacco,  to  give  a  person  a  severe  nausea,  in  order  to  secure  a  heavy 
fee  for  making  him  well  again. 

Chesnut  (1902,  p.  321-322)  tells  of  the  knowledge  of  this  plant 
by  the  Indians  of  Mendocino  County,  Cal.,  and  their  use  of  it  for 
medicinal  purposes. 

Hunt  published  an  abstract  in  1902  announcing  the  discovery  of 
the  alkaloid. 

In  a  copy  of  McCarthy  (1903),  apparently  annotated  by  the 
author,  the  statement  is  made  that  Zygadenus  glaberrimus  and 
Z.  leimanfhoides  are  poisonous. 

Nelson  (1906)  demonstrated  by  feeding  experiments  the  poisonous 
effect  of  Zygadenus  upon  sheep. 

REVIEW  OF  PHARMACOLOGICAL  WORK.» 

The  bulbs  of  Zygadenus  paniculatus  were  found  by  Collier  (1882) 
to  give  several  alkaloidal  reactions,  but  the  first  attempts  to  isolate 
and  determine  ,  the  chemical  and  toxic  properties  of  the  poison  of 
Zygadenus  seem  to  be  those  of  Keid  Hunt,2  special  expert  of  the 
Bureau  of  Plant  Industry  in  1901,  who  worked  with  the  leaves  and 
flowering  tops  of  Z.  venenosus.  Hunt  prepared  an  alcoholic  extract 

1  The  review  of  pharmacological  work  was  prepared  by  Dr.  Reid  Hunt,  of  the  Harvard  Medical  School. 

2  Hunt's  results  were  submitted  in  a  report  to  the  Department  in  1901  and  also  reported  at  a  meeting  of 
the  American  Physiological  Society.    (Hunt,  1902.) 


and  removed  various  oily  and  resinous  substances  by  precipitation 
with  water  and  extraction  with  petroleum  ether.  These  resinous 
bodies  were  not  toxic.  Vejux-Tyrode  (1904)  later  obtained  similar 
resinous  bodies  to  which  he  ascribed  a  high  degree  of  toxicity,  but 
Heyl  and  Hepner  (1913)  could  not  confirm  this. 

Hunt  purified  the  extract  further,  and  then,  by  extraction  with 
chloroform,  obtained  an  amorphous  substance  alkaline  to  litmus  and 
giving  the  usual  alkaloidal  reactions.  It  was  very  slightly  soluble  in 
water,  but  readily  soluble  in  dilute  acids.  When  treated  with  con- 
centrated sulphuric  acid  this  substance  dissolved  with  the  formation 
of  an  orange-yellow  solution;  the  color  soon  became  a  blood  orange, 
and  finally  a  bright  cherry  red.  This  play  of  colors  corresponds 
almost  exactly  to  that  caused  by  cevadin  and  to  that  recently 
described  by  Heyl,  Hepner,  and  Loy  (1913)  for  zygadenin,  an 
alkaloid  obtained  by  them  from  Zygadenus  intermedius.  Hunt 
found,  as  did  Heyl,  Hepner,  and  Loy  later,  that  the  alkaloid  was  not 
readily  extracted  with  ether.  When  the  alkaloid  or  mixture  of 
alkaloids  was  further  purified,  dissolved  in  alcohol,  and  the  alcohol 
allowed  to  evaporate,  a  clear,  glassy  residue  with  a  few  cubes  or 
prisms  was  obtained.  This  began  to  darken  at  185°  C.  At  197°  C. 
part  of  it  melted  to  form  a  red  solution,  but  all  of  it  did  not  melt 
until  a  temperature  of  220°  C.  was  reached.  It  is  quite  probable  that 
this  mixture  consisted  in  part  of  the  alkaloid  since  isolated  by  Heyl, 
Hepner,  and  Loy  and  named  by  them  zygadenin.  Zygadenin  crys- 
tallizes from  alcohol  in  " orthorhombic  blocks"  and  melts  to  a  red  oil 
at  200°  to  201°  C.  Hunt  pointed  out  a  number  of  resemblances  and 
also  certain  differences  between  the  reactions  of  the  alkaloids  obtained 
from  Zygadenus  and  those  given  by  cevadin  and  other  veratrin 
alkaloids  and  concluded  that  both  chemically  and  pharmacologically 
the  two  series  were  closely  related. 

Tor  aid  Sollman,  in  a  report  submitted  to  the  Department  of  Agri- 
culture in  1903,  stated  that  he  could  find  no  poisonous  principle  in 
Zygadenus  other  than  the  alkaloid  or  mixture  of  alkaloids  found  by 
Hunt. 

These  results  were  confirmed  by  Slade  (1905)  and  by  Heyl,  Hepner, 
and  Loy.  The  latter  authors  carried  the  work  to  the  point  of 
isolating  in  pure  form  an  alkaloid  which  they  named  zygadenin, 
although  the  question  whether  this  may  not  be  identical  with  some 
one  of  the  veratrin  alkaloids  is,  perhaps,  still  open.  It  may  also  be 
doubted  whether  zygadenin  is  the  most  important  toxic  agent  in 
Zygadenus,  for  these  authors  quote  Mitchell  as  reporting  that  "it 
(zygadenin)  kills  guinea  pigs  slowly  and  only  in  comparatively  large 
doses."  Hunt  found  4  milligrams  per  kilo  of  his  alkaloidal  prepara- 
tion to  be  fatal  to  rabbits  in  an  hour  or  two.  Sollman  found  about 
the  same  amount  of  cevadin  to  be  fatal. 


4  BULLETIN   125,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

Hunt  found,  as  did  Heyl  and  Raiford  (1911),  that  the  leaves  and 
flowering  tops  contain  more  of  the  alkaloid  than  the  bulbs.  By 
performing  an  extensive  series  of  experiments  on  animals  with  the 
Zygadenus  alkaloids,  he  found  that  their  action  was  in  all  essential 
particulars  the  same  as  that  of  veratrin.  They  were  very  irritat- 
ing to  the  mucous  membranes,  as  was  the  powdered  plant  itself; 
they  produced  an  intense  burning  sensation  and  a  very  acrid, 
bitter  taste  in  the  mouth;  when  applied  to  the  skin  in  alcoholic  or 
chloroform  solution,  they  caused  a  burning,  painful  sensation,  but 
the  spot  later  became  anaesthetized;  they  had  the  typical  veratrin 
effect  upon  the  muscles  and,  as  kymograph  experiments  showed, 
affected  the  respiration,  blood  pressure,  and  heart  in  the  same  way 
as  does  veratrin.  It  was  also  shown  that  the  death  of  animals 
poisoned  with  Zygadenus  was  hastened  by  attempts  to  arouse  them. 
This  was  attributed  to  the  rapid  failure  of  the  respiration,  circulation, 
and  the  muscular  system.  It  was  concluded  that  under  laboratory 
conditions  (and  probably  under  field  conditions)  an  essential  part  of 
the  treatment  should  consist  in  allowing  the  animals  to  rest. 

Hunt  also  isolated  the  alkaloids  from  the  urine  of  animals  poisoned 
with  Zygadenus.  He  found  that  they  were  excreted  with  the  urine 
quite  rapidly  and  demonstrated  that  under  laboratory  conditions  it 
was  often  possible  to  save  the  life  of  poisoned  animals  (rabbits,  sheep, 
etc.)  by  the  administration  of  diuretic  drugs  (caffein,  theobromin, 
sodiosalicylate) .  Atropin  and  strychnin  seemed  to  hasten  death. 

Solhnan,  after  satisfying  himself  that  the  toxic  action  of  Zygadenus 
is  identical  with  that  of  veratrin,  made  a  study  of  poisoning  by  the 
latter.  He  found  that  a  single  dose  often  caused  prolonged  sickness 
and  that  small,  repeated  doses  caused  no  tolerance,  but  increased 
the  susceptibility,  and  suggested  demulcents,  such  as  linseed  decoc- 
tion, to  counteract  the  corrosive  action  on  the  alimentary  tract. 

It  is  evident  from  these  chemical  and  pharmacological  studies  that 
the  poisonous  properties  of  Zygadenus  are  essentially  those  of  vera- 
trin, the  indications  for  treatment  being  the  same  in  the  two  cases. 

DESCRIPTION  OF  ZYGADENUS. 

The  genus  name  Zygadenus  is  used  in  this  paper  as  defined  in 
Robinson  and  Fernald's  revision  of  Gray's  Manual  and  in  Coulter  and 
Nelson's  New  Manual  of  Botany  of  the  Central  Rocky  Mountains. 
It  includes  the  three  genera,  Zygadenus,  Anticlea,  and  Toxicoscordion, 
of  Britton  and  Brown's  Illustrated  Flora.  The  plants  are  erect,  peren- 
nial, glabrous  herbs,  growing  from  a  rootstock,  or,  as  in  the  case  of  all 
the  western  species,  from  a  tunicated  bulb,  with  a  leafy  stem.  The 
leaves  are  grasslike,  long,  narrow,  and  keeled.  The  flowers  are  green- 
ish yellow  or  white,  borne  in  a  terminal  raceme  or  panicle.  This 


raceme  varies  in  the  different  species  from  an  almost  solid  head,  as 
seen  in  Plate  I,  to  a  very  loose,  elongated  panicle,  there  being  a  con- 
siderable range  of  variation  in  the  inflorescence  within  the  limits  of 
the  same  species.  The  perianth  is  spreading,  withering-persistent, 
the  sepals  bearing  one  or  two  glands  near  the  base.  The  stamens  are 
free  or  attached  to  the  bases  of  the  segments.  The  capsule  is  three 
lobed  and  dehiscent  to  the  base  in  maturity. 

The  species  of  Zygadenus  are  spring  and  summer  plants.  On 
May  8,  1913,  in  the  neighborhood  of  the  Greycliff  station,  Mont., 
Z.  venenosus  was  about  4  inches  high,  the  largest  plants  not  exceeding 
6  inches,  and  the  flower  scape  was  not  visible.  On  May  11  the  plants 
were  in  bud,  and  they  blossomed  through  -the  month  of  June.  Seeds 
were  formed  the  last  of  June  and  early  in  July,  and  after  the  middle 
of  August  the  plants  had  largely  disappeared. 

Zygadenus  elegans  was  in  full  blossom  near  Red  Lodge,  Mont.,  on 
July  20,  at  an  altitude  of  approximately  6,000  feet.  In  1910  Zyga- 
denus coloradensis  was  in  blossom  in  Colorado  at  about  the  same 
time  (July  20)  at  an  altitude  of  about  10,000  feet. 

In  Montana,  Zygadenus  venenosus  grows  typically  at  lower  levels 
than  Z.  elegans.  As  stated  by  Chesnut,  its  favorite  habitat  is  in  the 
shallow  ravines  occurring  on  hillsides.  It  does  not  grow  abundantly 
on  dry  hillsides  nor  in  wet  ravines,  but  it  is  very  commonly  found 
in  the  shallow  depressions  on  the  north  slopes  of  bench  lands.  Z. 
elegans  grows  at  higher  levels  (Rydberg  gives  as  its  limits  6,500  to 
12,500  feet)  and  in  locations  where  more  water  is  available  than  is 
necessary  for  Z.  venenosus.  While  it  grows  readily  on  hillsides,  it 
reaches  its  best  development  in  size  in  distinctly  wet  places,  some- 
times immediately  in  contact  with  rivulets. 

In  -  California  and  Oregon,  Zygadenus  venenosus  grows  in  the 
meadows,  while  Z.  paniculatus  grows  upon  the  hillsides.  Z.  veneno- 
sus is  more  common  on  north  slopes  and  Z.  paniculatus  on  south 
slopes. 

The  species  of  Zygadenus  may  grow  as  more  or  less  scattered  indi- 
viduals, but  sometimes  they  are  massed  together  in  large  areas, 
including,  perhaps,  several  acres,  in  which,  at  the  time  of  flowering, 
they  seem  to  be  the  principal  vegetation  and  give  a  characteristic 
greenish  yellow  color  to  the  landscape. 

The  species  of  Zygadenus  are  distributed  very  widely  in  the  United 
States  and  are  found  as  far  north  as  Alaska.  They  occur  most 
abundantly  from  the  Rocky  Mountains  west  to  the  Pacific,  and  their 
importance  as  stock-poisoning  plants  is  confined  almost  entirely  to  this 
part  of  the  United  States.  Plate  I  shows  the  general  appearance  of 
Zygadenus  venenosus.  This  is  an  Oregon  plant  and  shows  the  flowers 
as  they  appear  at  the  beginning  of  blossoming.  Later,  the  raceme  is 


6  BULLETIN   125,   U.    S.   DEPARTMENT   OF  AGRICULTURE. 

more  extended,  as  shown  in  Plate  II,  which  is  reproduced  from  a 
photograph  of  a  Montana  plant.  Plate  III  shows  the  plant  after 
the  seed  is  formed. 

COMMON  NAMES  OF  ZYGADENUS. 

The  species  of  Zygadenus  are  known  under  a  large  number  of  pop- 
ular names.  The  most  common  perhaps  is  death  camas.  In  the 
Northwest  perhaps  lobelia  is  the  name  used  even  more  generally  than 
death  camas.  Other  names  are  soap  plant,  alkali  grass,  water  lily, 
squirrel  food,  wild  onion,  poison  sego,  poison  sego  lily,  mystery  grass, 
and  hog's-potato.  Z.  glaberrimus  is  said  to  be  called  cow-grass. 

POISONOUS  SPECIES  OF  ZYGADENUS. 

The  following  species  of  Zygadenus  are  said  to  be  poisonous:  Z. 
elegans,  Z.  falcatus,  Z.  fremontii,  Z.  glaberrimus,  Z.  intermedius,  Z. 
mexicanus,  Z.  nuttallii,  Z.  paniculatus ,  Z.  venenosus. 

This  list  is  given  hi  accordance  with  the  statements  of  various 
authors,  and  no  attempt  has  been  made  to  revise  it  from  the  stand- 
point of  the  systematic  botanist.  Apparently  all  species  of  this  genus 
may  be  presumed  to  be  poisonous.  Even  Zygadenus  coloradensis , 
which  has  been  shown  not  to  be  injurious  to  stock  in  Colorado,  has 
the  same  poisonous  principle  as  the  other  species,  but  in  smaller 
quantity. 

LOSSES  OF  LIVE  STOCK  BY  ZYGADENUS. 

As  already  stated,  there  is  reason  to  think  that  deaths  of  cattle  and 
horses  from  Zygadenus  poisoning  are  not  numerous.  With  sheep, 
however,  the  losses  .are  very  heavy,  but  it  is  impossible  to  make  even 
an  approximate  estimate  of  these  losses.  It  is  probable  that  they 
are  much  greater  than  is  generally  supposed,  for  in  the  sheep-grazing 
regions  many,  perhaps  most,  of  the  herders  do  not  know  the  plant  and 
consequently  do  not  recognize  it  as  the  cause  of  illness  and  death  in 
the  bands  under  their  charge.  The  lupines,  without  any  doubt,  have 
been  blamed  for  many  of  the  cases  of  poisoning  by  Zygadenus. 

Chesnut  and  Wilcox  (1901,  p.  53)  state  that  636  sheep  died  from 
Zygadenus  poisoning  in  Montana  in  1900  and  that  3,030  were  poisoned. 
In  one  locality  in  Wyoming  500  sheep  died  out  of  a  total  of  1,700 
poisoned,  and  in  one  county  it  was  said  that  20,000  died  in  1909.  The 
writers  of  this  paper  investigated  a  case  in  Montana  in  which  500  sheep 
died  within  a  few  hours,  the  probable  cause  being  Zygadenus. 

There  is  no  doubt  that  this  plant  is  one  of  the  sources  of  heaviest 
loss  to  sheep  owners,  especially  in  Wyoming  and  Montana.  There  is 
good  reason,  too,  for  thinking  that  many  of  the  losses  in  Oregon, 
Utah,  and  California  which  have  been  ascribed  to  other  plants  were 
really  caused  by  Zygadenus. 


Bui.  1  25,  U.  S.  Dept.  of  Agriculture. 


PLATE  I 


ZYGADENUS  VENENOSUS  FROM  KLAMATH  AGENCY,  OREG. 


Bui.  125,  U.  S.  Dept.  of  Agriculture. 


PLATE 


ZYGADENUS  VENENOSUS  FROM  MONTANA,  IN  BLOOM. 


Bui.  125,  U.  S.  Dept.  of  Agriculture. 


PLATE 


x 


ZYGADENUS  VENENOSUS  FROM  MONTANA,  IN  FRUIT. 


Bui.  125,  U.  S.  Dept.  of  Agriculture. 


PLATE  IV 


FIQ.  1.— SHEEP  No.  160,  SHOWING  SALIVATION  AND  POSITION  INDICATING 

NAUSEA. 


FIG.  2.— SHEEP  No.  192,  SHOWING  SALIVATION  AND  ATTITUDE  INDICATING 
NAUSEA  AND  GENERAL  DISCOMFORT. 


ZYGADENUS,   OR  DEATH   CAMAS.  7 

ANIMALS  POISONED  BY  ZYGADENUS. 

Swine  are  said  to  eat  Zygadenus  bulbs  with  no  bad  results  (Parsons, 
1904,  p.  8). 

Cattle  are  susceptible  to  the  poison  and  there  are  reports  of  result- 
ing deaths.  So  far  as  has  been  learned,  however,  deaths  of  cattle 
from  this  cause  are  not  common,  and  it  is  not  especially  to  be  feared 
by  the  cattlemen. 

Many  cases  of  horses  poisoned  by  this  plant  are  reported.  The 
animals  are  made  very  sick,  but  apparently  most  of  them  recover. 
Mr.  Uttermohl,  of  Bigtimber,  Mont.,  who  has  had  considerable  expe- 
rience with  Zygadenus,  is  of  the  opinion  that  some  of  those  that 
recover  are  permanently  injured. 

Sheep  are  the  animals  most  frequently  poisoned.  This  is  probably 
due  in  part  to  a  greater  susceptibility  to  the  toxic  principle  of  Zyga- 
denus, but  very  probably  it  is  to  a  considerable  extent  due  to  the  way 
in  which  sheep  are  managed  upon  the  range.  While  grazing,  they  are 
frequently  herded  rather  compactly,  so  that  they  eat  the  forage  closely, 
and  when  passing  over  a  Zygadenus  area  many  of  them  may  eat  a 
large  quantity  of  this  plant. 

The  cases  of  human  poisoning  are  mostly  of  children,  who  find 
the  bulbs  attractive  and  sometimes  collect  them  instead  of  the  edible 
camas,  species  of  Calochortus  and  Camassia.  Most  of  these  cases 
recover,  but  there  have  been  a  number  of  fatalities. 

SYMPTOMS  PRODUCED  BY  ZYGADENUS  POISONING. 

With  the  exception  of  the  work  of  Chesnut  and  Wilcox,  nothing 
has  been  published  in  regard  to  the  symptoms  exhibited  by  grazing 
animals.  These  authors  (1901,  p.  61)  state  that  the  principal 
symptoms  of  poisoning  in  sheep  are  salivation,  nausea,  uneasiness, 
staggering,  muscular  incoordination,  paralysis,  and  convulsions. 
The  animals  sometimes  lie  many  hours  before  death.  The  writers 
mentioned  state  also  that  cattle  and  horses  have  spasms. 

Several  investigators  have  mentioned  some  of  the  symptoms  in 
man.  Heller  (1909,  p.  52)  gives  the  symptoms  (quoting  from 
Dr.  Lee,  of  Carson)  as  "nausea,  headache,  followed  by  more  or  less 
stupor."  He  states  that  the  heart's  action  was  lessened  in  frequency, 
while  the  strength  of  the  pulse  remained  normal.  The  respirations 
were  almost  normal.  In  another  case  vomiting  was  followed  by 
the  loss  of  all  power  of  feeling. 

Heyl  and  Raiford  (1911,  p.  64)  and  Hunt  (manuscript)  speak 
of  the  irritating  character  of  the  dust  when  the  dry  plant  is  being 
ground,  which  leads  to  sneezing  on  the  part  of  those  doing  the  work. 

The  Lloyds  (1887)  give  as  symptoms  in  man  "  extreme  thirst,  con- 
stant vomiting,  dilation  of  the  pupil,  coma,  and  inflammation  of  the 
stomach."  They  also  say  that  one  case  had  very  violent  convulsions. 


8  BULLETIN  125,   U.    S.   DEPARTMENT   OF  AGRICULTURE. 

Chesnut  (1902,  p.  321)  says  that  the  symptoms  in  poisoned 
Indians  are  "  burning  and  smarting  in  the  mouth  and  esophagus, 
dumbness,  nausea,  profuse  vomiting,  foaming  at  the  mouth,  dizzi- 
ness, and  mania." 

Mitchell  and  Smith  (1911)  experimented  with  the  extract  on  guinea 
pigs,  both  by  subcutaneous  injection  and  by  feeding  per  os,  and  found 
salivation,  vomiting,  excitement,  paralysis  (first  of  the  hind  legs), 
rapid  respiration  becoming  slow  and  labored,  heightened  reflexes, 
spasms,  heartbeat  slowed,  and  death,  under  fatal  dosage,  in  20  to  30 
minutes.  When  injected  into  dogs  under  anaesthesia,  the  general 
effect  was  to  reduce  the  rate  of  heartbeat  and  respiration  and  to 
produce  marked  intestinal  peristalsis.  The  heart  stopped  before 
the  cessation  of  respiration. 

Hunt,  Vejux-Tyrode,  and  Mitchell  and  Smith  experimented  on 
frogs,  producing  paralysis,  which  showed  itself  in  an  inability  to 
draw  up  the  legs  readily  after  extension.  Hunt  considers  that  it 
produces  an  effect  directly  on  the  muscles  as  well  as  on  the  central 
nervous  system. 

Chesnut  and  Wilcox  (1901)  and  Hunt  (manuscript)  experi- 
mented with  rabbits,  Hunt  stating  that  the  rabbits  exhibited  saliva- 
tion, nausea,  muscle  changes,  heightened  reflexes,  and  convulsions. 

Summarizing  the  published  statements  in  regard  to  the  symptoms 
of  Zygadenus  poisoning,  it  may  be  said  that  the  most  evident  symp- 
toms in  the  higher  animals  are  salivation,  nausea,  more  or  less  com- 
plete paralysis,  reduced  rate  of  heartbeat  and  respiration,  and  con- 
vulsions. The  results  on  frogs  are  not  so  marked,  as  would  be  ex- 
pected from  the  less  complicated  nervous  system,  and  the  principal 
thing  noticed  apparently  is  paralysis. 

GENERAL  STATEMENT  OF  EXPERIMENTAL  WORK. 

Experimental  work  upon  Zygadenus  has  been  carried  on  for  five 
seasons,  in  1909  and  1910  at  Mount  Carbon,  Colo.,  and  in  1912,  1913, 
and  1914  at  Grey  cliff,  Mont.  Table  I  gives  a  summary  of  these  ex- 
periments. In  1909  six  head  of  cattle  were  fed  experimentally  on 
Zygadenus  coloradensis  (Table  I,  section  A).  In  1910  a  steer  and 
four  sheep  were  fed  (Table  I,  sections  B  and  E).  In  1912  there  were 
18  cases  of  experimental  feeding  of  Zygadenus  venenosus  to  sheep 
(Table  I,  section  F).  In  1913  Zygadenus  venenosus  from  the  neigh- 
borhood of  the  station  was  fed  to  61  sheep.  In  this  section  of  the 
table  are  also  given  the  results  of  one  experiment  in  feeding  Zyga- 
denus venenosus  from  the  Stanislaus  National  Forest,  CaL,  to  a  sheep. 
In  1913  Zygadenus  elegans,  collected  near  Red  Lodge,  Mont.,  was 
fed  to  6  sheep  (Table  I,  section  H).  In  1914  there  were  110  cases 
of  feeding  of  Zygadenus  venenosus  to  sheep  (Table  I,  section.  I)  and 
five  experiments  of  feeding  to  sheep  Zygadenus  elegans  from  the 


ZYGADENUS,   OB  DEATH   CAMAS.  9 

Fishlake  National  Forest,  Utah  (Table  I,  section  J).  There  were 
also  two  experimental  feedings  o£  Zygadenus  paniculatus  from 
Ephraim,  Utah  (Table  I,  section  K).  Three  head  of  cattle  in  1913 
were  fed  upon  Zygadenus  venenosus  (Table  I,  section  C),  and  a  horse 
was  fed  twice  upon  Zygadenus  venenosus  and  once  upon  Zygadenus 
elegans  (Table  I,  section  D). 

So  far  as  possible,  the  feeding  experiments  were  carried  on  under 
natural  conditions.  To  this  end  the  animals  were,  ordinarily,  de- 
prived of  food  for  about  24  hours,  and  then  the  plant  to  be  tested  was 
offered  to  them.  If  they  did  not  eat  readily,  they  were  tempted  by 
mixing  the  plant,  sometimes  ground  up,  with  hay  or  grain.  As  it 
was  difficult  to  get  any  large  number  of  cases  by  feeding,  on  account 
of  the  dislike  of  the  animals  to  the  plant,  resort  was  had  to  drenching 
and  forced  feeding.  In  the  drenching  experiments,  the  plant  was 
ground  and  suspended  in  sufficient  water  to  make  the  administration 
possible,  the  drenching  being  done  in  most  cases  with  the  animal 
upon  its  haunches.  Forced  feeding  was  conducted  in  some  cases 
by  placing  the  plant  by  hand,  a  little  at  a  time,  in  the  animal's 
mouth.  In  the  majority  of  experiments  in  forced  feeding,  however, 
a  veterinarian's  ordinary  balling  gun  was  used,  and  the  ground  material 
was  fed  as  fast  as  the  animal  would  swallow  it. 

The  terms  under  "Severity  of  illness"  are  used  in  the  following 
way: 

"Not  sick"  includes  cases  in  which  no  symptons  appeared. 

"Symptoms"  includes  cases  in  which  there  was  slight  salivation  for  a  few  minutes, 
some  regurgitation,  some  licking  of  the  lips,  indicating  nausea,  or  indications  of 
uneasiness. 

"Slightly  sick"  includes  those  in  which  salivation  was  continued  for  an  hour  or 
more,  with  considerable  regurgitation.  Depression,  slightly  labored  respiration,  and 
temperature  reduction  may  occur. 

"Sick"  includes  cases  exhibiting  vomiting,  weakness,  and  sometimes  hyper- 
sensitiveness  and  trembling. 

"Very  sick  "  cases  were  characterized  by  prostration,  extreme  respiratory  difficulty, 
and  subnormal  temperature. 

47698°— Bull.  125—15 2 


10 


BULLETIN   125,    U.    S.    DEPARTMENT    OF   AGRICULTURE. 


^ 


o 

"c 
•^ 


^ 

^ 

I 


I 

^ 


M 


T   I 


EH       ^ 


.a 

® 

^ 

1 

"ft 
d 

4> 

Location  from 
which  plant  used 
was  obtained. 

a 
1 

"S 

Station. 

i.    ! 

••  X  X  O  ^  ^  r?  X  o 
M  r-i  r—  i  r—  i  f^  Q  +J  i—  i  M  rH 

«           £ 

lountofgr 

Ill's! 

&%"*£ 

O 

If  -&  S      . 

« 

-!°?               §•§». 

QO  1-1  £*(N  10  ^  8  . 

H 

03 

b  b 

d 
•3 

i 

*  o  > 

J 

PH 

1:1:1 

.2  S, 

s 



the  form  of 

s.] 

! 

•  o  o  o  o     o                c 

1 

• 

OO  GO  O  OOOC 

"l~l  u? 

d 

1 

t  the  weight  is  s 
anumber  of  exp 

Severity  of  il] 

•S  O  0  O  O        O                       C 

WTJ-d-d-d     'd               *d 

^0     •         •     ; 

e 

is 

to  w  p^  o 

3  2s*  "o  * 

ft  P,  'wrS  r§  5  °  Sf 

S  6  d0  -s  £ 

F*>  >>'rt  t2  >i 
CQ  CQ  <H  O2 

-e  given  dry  material;  bu 
ing  been  determined  by 

Part  of  plant  used  (fed 
unless  otherwise 
stated). 

HI    1 

4 

1        g 

>d         ! 

d          c 

§         . 

l  pi  ||  f  1  1 

2  ^2*0  B  :£  1  S^S-i 
w  _  2W  2  'g  ^  3^2-g® 

s|o  «^|ls§ts3  S^of^SSc 

^  HH.-;  i^  i-;  i-J  M 

ll 

1 

:  i  : 

>f5 

'  the  serial  nun: 
dry 

.9 

e 

*o 

SsSla  -         « 

•333  §t   |            | 

nt- 

1         Sl 
>              « 

-^  ^  S^es  S  "=2  •<  ^« 

a3  3  S3o  3  23  3  52 

?a  s  s^  s  s  s  iss 

II  I  it  3  3  3  I< 

a 

k  (*)  precedi 

o  ^ 

ll 

^'ft 

|SSS      ; 

• 
>            e 

<)  O5  IQ  OOO1  O  rH  00  •*!  W 

C»  iO  >-l 

i  by  an  asteris 

I 

8 

f1"      ' 

}      1 

n  i  i  §  §  s& 

2 

1 

si     :  :  :  :  :           si 

•      N 

i     :                         si 

d           pj 
^          .2 

§••:::::            §.. 

•       1.. 

:     i                      !.a 

[Animals  de 

03 
.1 

P 

^Sddddd      o         J  |  ,< 
•<°                                  H'° 

j       H  §H 

d 

,^  gj  J.  ,„  WJd^  2  ^ 

3  d  d  i2  d  ^Sdddc 
$X  K  Pf  X  03|^  }25  ^i^ 

ft                                                        &3 

ZYGADENUS,    OR  DEATH    CAMAS. 


11 


o'      o'      o 

ft    ft    Pi 


p      p   p      p        ppp  pp 


TJ<  ,-1  ,-H  t—  <M  -f 

co       o       co  t^-       o       -r 

I-H      06      oo          o      i-J      c4 


^  >> 
Sg 

S-y 


.  », 

-2-d 


«  :- 

mm 


CQ      C3Q  P 


ft   ^ 

l«1 

aucP 


denu 
nchin 
m  pe 


m  Z 
in 
po 


ick  fro 
killed 
with 
mang 

ympto 


a  galas   a-aap 
S-i|£|s  |2* 


in 


•         P*>        C*> 

IM'I^     *3      "3 

S<N         l^>          H-s 

j 

So      o      o 

888       c 

§     §     d       ^ 

I 

'   ^. 

c 
T: 

i 

^ 

»            ^ 

i  •§ 

j» 

*         ^ 

a 
,> 

c 

T— 
*  k- 

g 

k 

« 
.  > 

c» 

>                          > 

§     §     § 

"^ 

3 

"H 

'E 

^ 

1 

_ 

_ 

*~ 

^~ 

^ 

H- 

)  — 

t-: 

OOC^ 


r^M                                                                                                           r^«                           rJM                   Hf)          MM                                                               r*< 

CO         1C         !•«               •*         t~        R               t-  O                      00               t^        t2               lo                      I"  1C  O> 

223                                 32 

St-             CO                                                                 HN                       CO 
t*             iO                                                                <N                         GO 

{?§            §8 

d                                                                   ;                                                                ; 

^oddd          odd          do             d          do          d             odd 

do                 d 

BULLETIN   125,   U.    S.   DEPARTMENT   OF   AGRICULTURE. 


5S 


1910  at 
Continued 


p    pp    p    p    p  pp        p        pp    p 


§.-<*<c 
42o 

>_,r-I 


O       (N  00 
iOCDiO 


i 


°  0  0  0  C>  " 


;       t>, 


I  '..3 
:  :.S 


&|i| 

S3. -2 


525    p    p 


:* 

S.2 


•^  2 


Sfl 


nd 


1909 
Mon 


Zyg 


Part  of  plant  used  ( 
unless  otherwise 
stated). 


!    !  o    !-5  o 

i  ig  ;|g 


in  alfalfa 
drench) 

tems, 
nch). 
ch 


dre 
dre 


Leav 
Leav 

Lea 
bu 
Leav 


igfl 

•  a  55  a 


S       8S; 


288 


eed 


3  : 


3  : 


S3    c3c3    M 

>,      (»>,      0. 

1    II    1 


1-1  C<l 

'tuo 


iH        C4 

"5      o 
10      co 


CO  CO       OO 

§8£    S 


f 


—  S 


ig 


o^eO 

13 

Ig1 


o^lIS^Illl    3    33    3    3 


£?£ 
33 


do     o 

ZK     K 


ZYGADENUS,    OR  DEATH    CAMAS. 


13 


I  III  I  Sill  III  b|  Illl  I  II  I  I  II  I  Sill 


>O        00  CN        O 

OO         CO  i— I         CO 

co     cooo      •* 


>  ooo      o< 

I  IM  00        CC  C 

)  !>.  1--          rH  5 


T-HT-H     *t^  10       CNCO       <N 


o      oo 


.2    \2 


1*1. 


SI  SI  . 
II  ilil 


l 


C.tjc 

|s 

m 


a   a 


K8 

MOQ 


and 

and 
h). 


i  .tss 
«s  .2 

Crt    V3    O    tfi    ®    _. 

iiiir 

H?J         rJ 


a   a§ 

3    3-d 


S- 


8  1  »|  d  d-d  8  §  o  of  d     88  1 

>  g  >  !  -0-0-0  >  g-o-o-a     >>& 


1JSf|£' 


. 

O  i-I  ^  13  rH  i-l  rHlMCMCN  CO  COCO 

1-1  ^  S  9  OO  OOOO  O  OO        l~       y~        '-"-'              o           .  «,     -  — 

O  O    g    C3  -rS-U  -U-ri-ri+->  -I-.  -U  ^-i            Q            O            OO                  -*5                    «       .«» 

'  -|-i°30  C0«5  10050CN  CO  01^         -t^          •«         -"-^                 50         J22rHr3 

q  qqq  qq  qqqq  q 

3  333  33  3333  3  ^_        ~        ~        ~~             ~       ^^^^ 

r^  (^h^H-s  h^h»  t-^r-st-sr^  1-5  r-s  h-»       K,       l-j       r-^  t-j             1-5       "<  •<  <l  •< 


33 


a?      eo 

3     q 


1>-       OO       T-i  r-l 


3       3       S 


IM        OO  00        CO-^O       O       £JO«5t^  OiOO  •*•*  eO<M-ft^  ^M 

rsi        O4Tt*  OS        O^OC^l        Oi       OivHOO  C^l^^  cot-*-  rHOr>-Tt<  O 

CO        O*  r-l  <N        CNCO(N        CO        00>O>OCO  (M  •*  i-H  OO  CM  <M  i-H  •*  CN  OO 

',-<  ........  eo  *  IH  i-J  T-H  eo  t-5  i-J    "  to  ^ 


(M(N  (N        "OOO-f 

iOt-~  i—  t       tOt-HO^O 


3   3   33  3  33  3  333  33   33  3   3  33  3  3  33   3   S3 


lO        OOO        O        O--IC35        O        O5  (N  CO  00        l>.i-HT»t        OcO  <NiOOi-H 

Oi       OiO>       O        COn>       T-H        O  *— i  T-H  o       OTHI-H        T^cji  O  i— I  O  O 

r-l        rH  rH        C<»        CNCNi-H        CM        CNCSCMCN        CMCNCN        CNi-H  CMCNCMCN 


O    00    O    OOO    O    0000    OOO    OO 

jz;    fcfc    fc    521^52;    }r    ' 


fcfcjz; 


dodo 


CN        CM  i-H        TH        CM        T-H  CN 

d      do      d      d      do 


d      d  d  d  d 


14 


BULLETIN   125,   U.   S.   DEPABTMENT   OF  AGRICULTUBE. 


b?c 

£1 

-3 

1 

f 

1 

1 

1 

2t 

1 

5? 

« 

*& 

03.3  v> 
ill 

Sdd          §£d      d      d          do 
•2QP         -g^Q     ft     Q         OP 

|    SS            S     S     S'| 

Ci 

A 

CQ                       PQ 

O                                                                     co 

>-( 

m  *g_ 

_: 

0     .0003             CO        (M       t-H        0             00 

05               05^ 

M<               10               >C05 

'S 

?%$ 

Sc 

q:>'wl§S^       ^2    SB    §    5       t-^cc 

CO              SS 

f3        °p        *lo 

1 

fe|c3  *   '           '       "     «o       ' 

•    • 

^ 

p  t  M  eg 

^  a 

<so 

"o 

_ 

S 

"3 

1 

; 

t>*    ' 

>H 

i 

| 

& 

^T 

> 

A 

g 

>*H 

0} 

0 

i 

§ 

i~-i 

PH 

p 

£ 

_?J 

1 

e 

>> 

TJ 

q} 

i 

ill} 

1 

-2 

'o 

a 

( 

- 

c 

O        O        O         O              C 

£ 

i 

-i 

o  S  •**  'Sb^ 

ilf&la 

c 

o 

'S 

p  t 
3  o 

c 

£ 

1 

« 

&H                   t2J 

EH£ 

K 

i 

^, 

"o 

^ 

^ 

|^ 

I 

,b 

5 

c 

t 

c 
-c 

c 
•c 

1 

ooo^l 
6       | 

J    1 

c 

3            *| 

®                   c 

( 

•»: 

q3          c 

^5         "C 

otsick.. 

^    § 

$ 

tz 

M           1 

ft              !? 

cc 

» 

in 

3 

g           gjg    OT^   ££ 

1 

1 

il         1 

t 

5            J-  ^ 

"S?      S  ^ 

|1 

Q 

"rt** 

fe       •fe_ofe_ofeLj 

| 

^ 

fe  *-<                  •? 

cc  O 

l^f 

11 

§|5|I|^ 

tc 

a*^      a 

!O 
^ 

^       5§5- 

|| 

i«! 

•as?  -s 

Q 

-3    -H    ~S    -<s 

t 

1 

™  m                 * 

'Sxj'bB            t? 

-/& 
11 

—  , 

|         ||      . 

"? 

r/5    (-1     W 

£ 

'c^ 

II 

^c 

c 
•c 

Ii  11  11  111" 

C 
~ 

c3  W) 

Ill              I 

•gl 

as 

_,  m  «  _-  IS  C 

111 

eo 

S 

PH 

CQ 

>H      M.      M      W 

1- 

h-^                             h- 

H 

1-5 

HH 

1 

a 

§? 

1 

•< 

I 

M 

si 

03 

III 

ft 

§ 
i 

i           = 

"3 

THj-Ht-4                  ^          S            O          *                  S"~ 

«         c5e5                 «5      c 

S          c 

flfl 

I 

( 
1 

» 

1 

i 

titiwi         j^j^             ^         ^>bl 

0  I  II     Ir 

^c 

3 

0> 

§ 

1-5 

•g 

s_ 

. 

^«S^H           ^-i      »o      oo      ^r           c*<r 

TJ.          r^^n                           ro          <-<          —ico 

SS 

SX, 

0 

1 

^'^OCO               51        S        08        S              ^T 

S            ^u?                                  S            5             ^^ 

§ 

I- 

|6   •                '     ^     co 

'         o                                 cT^     ^ 

| 

3 

t 

ft, 

I 

^ 

..•S3?      S    S    S    S       JS^ 

>     i1     si         I?  s     s     ss 

V 

§ 

|2S3       3          |    |       11       3       3                      S       3       S3 

5r> 
h. 

C 

S 

^ 

oast 

g          §                                              cc          £o 

1 

1 

S3  q 

•  S3* 

^ 

'S 

d 

PJ  o               d        ;        ;        ;        ; 

•  fl        '•                                            ; 

( 

**! 

.2 

J;  \          -^      •      •      •      •         • 

•  >  ••  •                            i 

t—t 

I 

||ss|^s  §  |  s     S^ftl§     l§         §  1     §     ii 

W 
_) 
to 

'% 
A 

Jidod^lo'dod         d  d  1  §  d         do*               55*        5*        5*5* 
Sp^g*f&Z5    jz;    jz;    Jz;       ^^gg^J        JzjJzj              Jz;    K        K        te 

•< 

1   >                 •'S 

p» 

H 

C5                W 

«• 

ZYGADENUS,    OR   DEATH    CAMAS. 


15 


ss 


«.s 

,0 


!S       8: 


S  : 


sins 


o  o  o  -2  o 


IS 
%* 

& 


.11 

C/3    W 

SS 

£5 


0     g^"" 


335^ 


S'-S 

C 


OOU  WQ}_*CAO 

TS-d-d     -d  >^  cs-d 


tems,  flowers, 
buds  (with 


o.2 
""^ 


^DQ 


a     9 

m     & 


000        O 


Leaves, 
flowers 


M  O  <M  CO 


<0  000         O 


IN  <i 


I 

322       2       2222 

•f  06  Q  O  1-1  i 


ooooo      oS 

22"    22 


8S    fe    ^r^ 
22    3    33 

001  |T  SJ2 


3       3. 


3    33 

sr  ^a 


11     B 


Illl 


o'  o'      o      66 


•°°-0-0     || 


TABLE  I.  —  Summary  of  feeding  experiments  with  Zygadenus  in  1909  and  1910  at  Mount  Carbon,  Colo.,  and  in  1912,  1913,  and  1914  at  Greycliff,  M 
Mont.—  Continued. 

BULLE1 

a| 

111 

O  £i,-*"^ 

111 

IN   125,   U.    S.    DEPARTMENT   ( 

0         odd  d         d  d      d  d      d         c 

.S       PPPP       pp    pp    p       p 

§ 

)F   AGRICULTURE. 

P       p    p       pp    pp    p 

ft! 

^  *  3          S  §  oo  co          "*  S      *"*  a?      S?          ot!          o          co»o          co  o      co  ro      03 

! 

I  « 

C 

— 

4 

IH      [ 

§  0        C 

i-d     T 

j              \ 

J 

•8 

b 
I      " 

c 

-r 

C 

P4    . 

':           ^ 

Remedy. 

SI? 

*u  73 

1 

-i 

0              C 

'd         t: 

Tannic  acid 
(in  capsule). 

Nnnfi 

II 

•st 
g.S§       ^ 
I^S 

Tannic  acid 
(in  capsule). 

Nonp, 

0              C 

-d        T 

•r 

C 
r 

.~ 

z 

(in  capsule). 
Nonp, 

c 
~ 

Severity  of  illness. 

Slightly  sick  

Sink 

4a 

^ 
| 

'to 

I   1 

CQ         a 

'w 

I    ' 

CO 

c 
— 

I 

0 

t 
}Z 

c 

-^ 

C 

> 
I 

X 

5 

1 
> 
a 

?! 

1 

* 

~ 
7. 

•  3 

w 

>  «    -g 

^       35 

Part  of  plant  used  (fed 
unless  otherwise 
stated). 

Ii 

->'O 

r3    ® 

|Ir 

c 
— 

c 
•c 

Leaves,  stems,  flowers, 
and  buds  (forced 
feeding). 

fin 

c 

-c 

c 
•c 

e 
- 

aves,  stems,  flowers, 
md  buds  (in  7  forced 
eedings). 
aves.  stems,  flowers. 

'rt       T3  JL       'C 

i  si  s 

S.        -T3 

«  II  1 

5"3M^    a 

rff!?l 

lowers  (drench). 
aves,  stems,  and 
lowers  (forced  feed- 
ng). 

Hn 

c 
~ 

4 

D 

y 

i 

^« 

flowers  (drench). 
...do.... 

3        J 

i-5         i- 

A 

1 

S 

I 
a 

"o 
9 

1  * 

c 
~ 

c 

T 

c^          c 

®       T 

s: 

p-^ 

c 

p 
c 

h 

0             C 

•d        T; 

c3          c 

®        -d 

H-3 

5         g^ 

lc^ 
a 

c 

T 

^ 

o| 

4!     i 

r 

rHi>ie<i          c-i          cs          T-H'C^          c<ic<ie^i-! 

i 
1 

5 

|s       3335         3    33            3       3       S    S       33    S3 

Anim 
Designation. 

sjg  : 

CO    • 
a,   i     . 

:  :  :        :  :     :  :     :                        :     :           :     :  :     : 

2  §  d         dddd         ddddd         d         d         do         c'dco'd 

1  * 
H 

ZYGADENUS,    OR   DEATH    CAMAS. 


17 


1 

d  d  d 
PPP 

od5 

QP.S 

d  d      P 

U 
| 

o' 

P 

.w 

P  ^ 

d 
P 

te 

d  d  o*          d 

d 

P 

3s 

IS 

S 

§ 

as 

0 

02 

O 

o 

2       S! 
t^-       t-~  < 


<M  T-I  <M  ^1 


S1 

.22 


ofl 

«& 

.28 


-5 
O   3 


o       .s  e    .s 


«  0  *"    .  o 

g  es 


^ 

S 

m 

>t 

73  o 
^-d 


S^; 


^5 


P-I 


llF"55^ 


£!il 

.s^sl 

o-O^J 
IftSl 

rfpaj 

T3^^       ^.^ 
C3  C  M 

r-it^ 

r°°- 


- 

" 


& 


S       c:S 


^iM        CO 

"5    3 


a  ^ 
>, 

3 


CO  CO  O  O 


- 

TP         O  *—  * 
0         O  ^H 


C<lCO  CD         ^* 

CO  »O  C^fcO 

OO  00  CO        w5 


i1    si's 


12    8       o 


333 

Is! 


lO  t^  (N  CO  Oi 

S  §  S  88 

d          d          d          d  d 


^        04?3  tN^CN  CN        S 

d      do          odd          d      d 


47698°— Bull.  125—1; 


TABLE  I.  —  Summary  of  feeding  experiments  with  Zygadenus  in  1909  and  1910  at  Mount  Carbon,  Colo.,  and  in  1912,  1913,  and  1914  at  Greydiff,  M 
M  ont—  Continued. 

Locationfrom  W 
which  plant  used  C^ 
was  obtained.  f 

r 
a 

CIN   125,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

i 

I  

®d             d             ddddo'dddd         odd             d         c 

g>    0            Q            QQO     00     0     Q     00         QQQ            Q         Q 

O 

^                 O 

§42^3               5              ^>ooooooooo5?T?'oo          ooSoo               oo          oc 
^H"**                      "*              -*r-oo      oooo      oo      t^     t-oo          oocooo              oo          oc 

! 

I      I    « 

d  c 

T3'C 

"08             8        O        C 

<B               CD        TJ        t 

Q        p» 

^ 

^ 

§         £ 

«         " 

(repeated 
doses). 
None  ...do  

d 

9  cb        g-t-?  p 
H  to        f^2 

Tannicacid1.. 

Pntn.ssinm  npr- 

,|  |||| 

yiLi  i 

illllil  i 

OPn      O      Q      < 

1 
e 

1 

2 

pig      c 

^ 

i  -S'S      ^ 

2  o  ^  •  K 

sE3  ^  £>  crt  £ 

1 
1 

"o 
>> 

! 

eg 

i 

:r, 
> 

s 

t 

•  1 

3      i 

j. 

! 

1     « 

>                     QQ 

£ 
'5 

I 

M    i    if 

33       £                 02                 CQOQOE 

i 

^ 

£ 
"a 

I 

0        C 

,    -d     -c 

Part  of  plant  used  (fed 
unless  otherwise 
stated). 

||4 

If 

Seed  heads,  fully  de- 
veloped (forced 
feeding). 
...do  

c 

-c 

0                   C 

-o             T: 

c 

0  C 

TTT: 

c 

T: 

c 

C 

"^  §  c 

1 

M 

0> 

"o 

Q 

:               i 

i 

• 

-*  :               i 

»  • 

^    5         -'         ^ 
t              t 

2  c 

^•C 

% 

8    ?5^       2SS3          S       53 

0*2 

^5  3 

II  • 

p  i    i    in  g 

OS       CO       00       00(N 

i-i  C^l  O3                    SO              00 

Animal. 

i 

<s 

§3    3          3          333 

0  Oi        r-                    O5                    iO  O<M 
Qy  **•      «^"                °Q 

SoOOOOO              OOO5O                    O5              S 

asSSssa       ££ 

^?!?SS2S        §^          8       S 

00        00        1-1        i-l                                                       <-> 

C 

.2 

"eS 

Q 

«§                 j  i  i 

So 

0 

IL  „     «     JJj  J«  gi  J  Js 

^§dd            hd             dddddo'ddo 

^d  d  d             d 

ZYGADENUS     OE  DEATH   CAMAS. 


19 


o          o  o 

£   %% 


20  BULLETIN   125,    U.    S.    DEPARTMENT    OF   AGRICULTURE. 

Following  are  the  details  of  three  cases  which  may  be  considered 
typical: 

Sheep  No.  193. — This  animal  (Table  I,  section  G)  was  a  2-year-old  ewe,  lent  for 
experimental  purposes  by  Mr.  Ole  Birk eland.  She  was  received  at  the  station  on 
May  9, 1913.  An  attempt  was  made  on  May  12  to  feed  to  her  the  bulbs  of  Zygadenus 
venenosus  ground  and  mixed  with  bran.  As  she  would  not  eat  this,  a  trial  was  made  on 
May  13  of  feeding  her  with  Zygadenus  tops,  but  these  also  she  refused  to  eat;  so  at  1.40 
p.  m.  of  the  same  day  she  was  drenched  with  200  grams  of  Z.  venenosus  bulbs  ground 
fine  and  suspended  in  water.  At  2.35  p.  m.  she  was  frothing  at  the  mouth  and  vomit- 
ing, with  violent  contractions  of  the  diaphragm  and  abdominal  muscles.  She  was 
lying  down,  but  was  able  to  stand.  At  3.50  p.  m.  she  was  still  frothing  at  the  mouth, 
but  was  fairly  strong.  At5.30p.  m.  her  temperature  was  101°  F.  She  was  fairly  strong, 
but  acted  as  though  in  much  discomfort.  On  May  14,  at  7  a.  m.  she  appeared  entirely 
normal,  and  at  8.30  she  was  turned  out  to  pasture. 

On  June  14, 1913,  she  was  kept  in  for  feeding,  and  at  8.15  a.  m.  she  was  fed  100  grams 
of  fresh  tops  of  Zygadenus  venenosus,  which  were  collected  on  June  12.  At  this  time 
the  plant  was  in  flower.  At  4.40  p.  m.  she  was  fed  200  grams  of  the  plant,  and  at  7.40 
p.  m.  135  grams. 

On  June  16,  at  7. 10  a.  m. ,  she  was  fed  200  grams;  at  6.40  p.  m. ,  200  grams;  and  at  7. 15 
p.  m.,  250  grams.  All  the  Zygadenus  fed  on  June  16  had  been  collected  on  the  pre- 
ceding day. 

On  June  17,  at  6.45  a.  m.,  all  the  Zygadenus  given  on  the  preceding  day  had  been 
eaten.  The  animal  appeared  bright,  but  showed  sensitiveness  to  sudden  noises  and 
there  was  some  trembling  of  the  surface  muscles.  At  7  a.  m.  she  was  run  around  the 
corral.  It  was  found  that  she  moved  in  a  stiff-legged  manner  and  was  somewhat  weak. 
The  stiffness  was  most  noticeable  in  the  hind  legs.  She  was  licking  her  lips  and  rub- 
bing her  nose  against  the  fence  and  moving  her  head  about  in  a  jerky  way.  At  8.45 
a.  m.  the  symptoms  were  about  the  same  as  at  7.  a.  m.  At  this  time  she  was  fed  200 
grams  of  Zygadenus.  At  11.30  a.  m.  and  1.50  p.  m.  she  was  fed  100  grams  of  Zygadenus. 
At  3  p.  m.  her  temperature  was  103.8°  F.  She  was  more  nervous  than  in  the  morning 
and  her  movements  were  somewhat  more  stiff.  The  jerking  movements  were  more 
pronounced  and  continuous.  All  the  Zygadenus  which  had  been  previously  given 
had  been  eaten.  At  8  p.  m.  the  symptoms  as  noted  at  3  o'clock  still  continued  She 
was  fed  a  little  alfalfa. 

On  June  18,  at  6.45  a.  m.,  the  sheep  was  trembling  almost  constantly,  with  frequent 
spasmodic  movements.  Her  legs  were  stiff  as  she  walked  about,  and  there  was  some 
lack  of  control.  She  was  dejected  and  dull  and  without  appetite.  At  9  a.  m.  she 
was  given  5  grams  of  tannic  acid.  At  9.40  she  was  given  4  ounces  of  Epsom  salts  in 
solution.  At  10.30  a.  m.  she  was  put  in  a  metabolism  cage,  in  order  to  collect  the 
excretions.  At  2  p.  m.  she  seemed  to  be  decidedly  better,  and  continued  in  about  the 
same  condition  throughout  th,e  afternoon. 

On  June  19,  at  6.30  a.  m.,  the  animal  trembled,  but  showed  no  other  symptoms. 
She  had  not  urinated  since  being  placed  in  the  metabolism  cage  at  10.30  a.  m.  on  the 
preceding  day.  At  8  a.  m.  she  was  taken  out  of  the  cage  and  fed  some  alfalfa.  The 
general  appearance  of  the  animal  was  better  than  on  the  preceding  day,  but  she  was 
stiU  unsteady  in  her  gait  and  exhibited  trembling  of  the  surface  muscles.  At  1  p.  m. 
she  defecated  as  the  result  of  the  dose  of  magnesium  sulphate  given  on  the  preceding 
day,  and  this  defecation  continued  in  a  mild  diarrhea.  At  3  p.  m.  she  urinated  for 
the  first  time  after  being  placed  in  the  metabolism  cage.  At  this  time  her  respiration 
was  148,  and  she  seemed  in  general  to  be  worse.  At  8  p.  m.  she  was  given  1  gram  of 
diuretin  in  solution,  and  returned  to  the  metabolism  cage.  During  the  afternoon  the 
animal  seemed  to  be  gradually  getting  worse.  When  standing,  her  hind  legs  were 


ZYGADENUS,    OE  DEATH   CAM  AS.  21 

drawn  forward  under  her.  The  muscles  of  the  legs  were  twitching  almost  continu- 
ously, and  it  was  with  difficulty  that  she  could  get  up  and  down. 

On  June  20,  at  6.30  a.  m.,  there  were  about  1£  pints  of  urine  which  had  accumulated 
through  the  night.  This  was  preserved  in  alcohol,  and  a  chemical  examination 
showed  that  it  contained  the  alkaloids  of  Zygadenus.  The  diarrhea  still  continued. 
The  general  condition  of  the  animal  was  nearly  the  same  as  the  preceding  night,  except 
that  she  appeared  a  little  stronger.  She  was  taken  out  of  the  cage  and  fed  alfalfa. 
At  2  p.  m.  she  was  somewhat  better  than  in  the  morning  and  had  an  appetite,  although 
she  still  preferred  to  lie  down.  At  this  time  she  was  given  1  gram  of  diuretin  in  solu- 
tion. At  7.50  p.m.  she  was  much  better,  standing  in  a  more  normal  manner  and  with 
no  noticeable  trembling.  On  June  22  she  was  turned  out,  apparently  all  right. 

On  July  15,  1913,  the  sheep  was  again  kept  in  for  feeding,  and  on  July  16,  at  10.30 
a.  m.,  she  was  given  200  grams  of  the  mature  heads  of  Zygadenus  venenosus,  consisting  of 
pods  and  seeds,  ground  and  mixed  in  bran. 

On  July  17,  at  9.25  a.  m.,  she  was  fed  270  grams  prepared  as  the  day  before,  and  at 
1.25  p.  m.  she  was  fed  180  grams.  At  7.45  p.  m.  she  was  fed  210  grams.  At  the  time  of 
the  last  feeding  she  showed  the  effects  of  the  poisoning.  She  did  not  move  with  the 
usual  freedom,  and  there  was  some  twitching  of  the  surface  muscles  of  the  body. 

On  July  18,  at  9.50  a.  m.,  she  was  fed  235  grams.  At  6.30  p.  m.  she  was  fed  220 
grams.  During  the  day  there  was  little  change  in  the  condition  of  the  animal. 

On  July  19,  at  7  a.  m. ,  the  symptoms  were  much  more  pronounced  than  the  preceding 
night.  There  was  stiffness  of  movement  of  the  legs,  licking  of  the  lips,  and  slight 
trembling.  This  stiffness  and  accompanying  clumsiness  were  more  pronounced  in 
the  hind  legs.  At  9  a.  m.  she  was  fed  255  grams  and  at  3  p.  m.  195  grams.  At  this 
time  the  animal  was  considerably  weaker  than  in  the  morning. 

On  July  20,  at  8.45  a.  m.,  all  the  Zygadenus  given  on  the  preceding  day  had  been 
eaten,  and  the  general  condition  of  the  animal  was  about  the  same  as  on  the  preceding 
night.  She  moved  with  some  difficulty  and  with  marked  stiffness  of  the  legs.  There 
was  trembling  of  the  surface  muscles  accompanied  by  some  shaking  of  the  head  and 
licking  of  the  lips.  She  was  unusually  sensitive  to  noise,  as  she  was  easily  startled, 
and  at  such  times  there  were  sudden  contractions  of  the  body  muscles.  She  had  much 
difficulty  in  raising  her  feet  sufficiently  to  get  over  elevations  of  3  or  4  inches. 

On  July  21,  at  3  p.  m.,  the  animal  had  improved  in  its  general  condition,  although 
the  symptoms  were  still  well  marked.  These  did  not  differ  from  those  seen  earlier  in 
the  sickness,  but  were  less  pronounced. 

On  July  22,  at  7  a.  m.,  the  animal  moved  about  fairly  well,  but  there  was  some 
trembling  of  the  surface  muscles,  especially  in  the  shoulders.  She  improved  during 
the  day  and  at  7  p.  m.  seemed  to  be  quite  normal.  On  July  23,  at  7.55  a.  m.,  she 
was  turned  out  to  pasture,  appearing  strong  and  active  and  showing  no  symptoms 
except  some  slight  trembling  when  handled. 

Sheep  No.  160. — This  animal  (Table  I,  section  F)  was  a  ewe  lent  by  Mr.  Ole  Birke- 
land  on  June  20, 1912.  On  July  19,  1912,  she  was  taken  in  for  feeding  with  Zygadenus 
venenosus.  At  11 .05  a.  m.  her  respiration  was  28,  pulse  26,  and  temperature  105°  F.  At 
11.25  a.  m.  she  was  drenched  with  125  grams  of  the  seed  heads  of  Zygadenus  venenosus 
suspended  in  water.  These  seed  heads  included  the  pods  and  seeds.  At  11.35  a.  m. 
there  was  a  little  frothing  at  the  mouth.  At  11.40  a.  m.  her  respiration  was  very  rapid 
and  irregular.  It  would  run  as  high  as  200  per  minute  for  perhaps  50  respirations, 
then  stop,  only  to  be  resumed  at  the  same  rapid  rate.  At  this  time  the  animal  had 
vomited.  At  12.55  her  pulse  was  95  and  very  variable;  her  temperature  was  104°  F. 
At  1  p.  m.  her  respiration  was  200  or  more  and  the  heart  action  regular  and  strong. 
She  was  then  given  a  solution  of  potassium  permanganate.  At  1.17  p.  m.  she  was 
getting  weaker  on  her  legs.  She  would  start  to  lie  down  and  nearly  fall,  but  would 
get  on  her  feet  after  a  minute  or  two  and  then  lie  down  again.  Her  respiration  was 
about  180  per  minute.  At  1.30  p.  m.  her  respiration  was  still  rapid,  the  mucous 


22  BULLETIN   125,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

membranes  of  the  mouth  somewhat  cyanotic,  and  the  ears  drooped.  At  1.47  p.  m. 
she  was  given  subcutaneously  8  grams  of  caffein.  At  1.49  p.  m.  she  threw  her  head 
up  and  held  her  breath  for  about  a  quarter  of  a  minute.  She  repeated  this  action 
several  times.  At  2.03  p.  m.,  her  temperature  was  100°  F.  The  animal  seemed 
somewhat  stronger.  Her  respiration  was  still  variable,  running  as  high  as  180  per 
minute.  Her  pulse  was  about  80.  She  was  still  frothing  at  the  mouth  and  appeared 
to  be  in  pain.  At  2.20  p.  m.  she  had  a  hard  time  to  breathe.  She  shook  her  head, 
staggered  about,  and  lay  down.  Her  respiration  was  slow  and  labored.  At  2.22  p.  m. 
her  respiration  was  getting  more  rapid.  At  2.23  p.  m.  the  animal  seemed  to  be  in 
great  pain;  her  breathing  nearly  stopped  for  a  minute,  but  started  again  in  a  panting 
manner.  Her  respiration  continued  irregular,  first  fast  and  then  slow  and  labored. 
At  3  p.  m.  her  temperature  was  100.2°  F.  and  her  respiration  84,  but  not  as  labored 
as  at  2.03  p.  m.  She  was  still  frothing  at  the  mouth.  Her  pulse  was  96  and  strong. 
At  3.30  p.  m.  her  respiration  was  160.  She  fell  upon  her  knees,  struggled  to  get  on 
her  feet  again,  but  finally  lay  down.  At  4.15  p.  m.  she  was  groaning  more  or  less  and 
staggered  as  she  attempted  to  walk.  Her  respiration  was  90.  At  4.30  p.  m.  she  was 
lying  down  and  her  respiration  was  very  nearly  normal.  Her  temperature  was  99.1°  F. 
At  5  p.  m.  she  was  down  again  and  in  pain;  groaning  continuously,  her  respiration 
slower  than  for  some  time  previous,  the  rate  being  about  60  per  minute.  At  5.04  p.  m. 
the  animal  was  lying  sprawled  out  upon  her  belly.  Her  respiration  was  168.  At 
5.38  p.  m.  she  appeared  very  stupid,  almost  as  if  sleepy.  She  was  given  subcutane- 
ously 6grains  of  caffein  sodiobenzoate.  At  5.45  p.  m.  her  temperature  was  99.4°  F.,  her 
respiration  120  and  very  variable,  and  her  pulse  96.  At  7.10  p.  m.  her  temperature 
was  99.7°  F.  Her  respiration  was  slow  and  variable.  After  expiration  there  would  be 
a  pause  followed  by  two  short  and  shallow  inspirations  close  together.  These  would 
be  followed  by  a  long  inspiration,  then  a  full  expiration  accompanied  by  a  groan. 
This  was  repeated  over  and  over  again,  the  whole  cycle  taking  about  20  seconds.  The 
animal  on  the  whole  seemed  to  be  brighter  than  at  6  p.  m. 

At  8  p.  m.  the  animal  was  given  5  grains  of  caffein  sodiobenzoate.  Her  temperature 
was  100.8°  F.,  respiration  10,  and  pulse  120.  At  10  p.  m.  her  temperature  was  100.2° 
F.,  pulse  120,  and  respiration  4.  The  inspiration  was  deep  and  the  expiration  was 
accompanied  by  a  groan.  At  10.55  p.  m.  her  temperature  was  100°  F.  At  11.15  p.  m. 
her  respiration  was  18  and  pulse  108.  Her  general  condition  was  unchanged. 

On  July  20,  at  7  a.  m.,  the  animal's  pulse  was  100,  temperature  100.8°  F.,  and  respi- 
ration 11 .  She  was  then  lying  with  her  head  bent  under  her  body  and  would  probably 
have  died  in  that  position  had  she  not  been  relieved.  She  seemed  at  this  time  uncon- 
scious. At  8.45  a.  m.  her  temperature  was  100.6°  F,  pulse  84,  and  respiration  12.  At 
10  a.  m.  her  respiration  was  10,  and  her  pulse  84.  The  animal  was  in  a  comatose  con- 
dition. At  10.50  a.  m.  her  respiration  seemed  to  be  getting  more  shallow.  At  11.15 
a.  m.  she  seemed  somewhat  brighter  than  earlier  in  the  day.  At  12  m.  her  temperature 
was  102.6°  F.,  respiration  12,  and  pulse  108.  During  the  afternoon  she  had  been  lying 
in  practically  the  same  position,  with  her  head  slightly  raised,  resting  upon  a  support. 
She  was  too  weak  to  move  herself  at  all.  At  3  p.  m.  her  respiration  was  12.  At  3. 30 
she  was  given  subcutaneously  10  c.  c.  of  whisky.  At  4.20  p.  m.  her  temperature  was 
102.8°  F.,  respiration  36,  and  pulse  116.  At  8.05  p.  m.  she  was  given  subcutaneously 
5  c.  c.  of  whisky.  At  9.30  p.  m.  her  temperature  was  104.6°  F.,  respiration  18,  and 
pulse  120. 

On  July  21,  at  5.45  a.  m.,  she  was  found  in  practically  the  same  condition  as  the 
preceding  night.  At  6.45  a.  m.  her  temperature  was  104°  F.,  respiration  24,  and  pulse 
148,  and  weak.  At  9.50  a.  m.  she  was  given  subcutaneously  5  drops  of  fluid  extract  of 
digitalis  in  8  c.  c.  of  whisky.  At  10.15  a.  m.  her  pulse  was  somewhat  stronger  than 
before  the  digitalis  was  given.  At  11  a.  m.  her  pulse  was  102,  temperature  104.6°  F., 
and  respiration  48.  At  11.15  a.  m.  her  respiration  was  fairly  deep,  but  was  somewhat 


ZYGADENUS,    OR   DEATH    CAM  AS.  23 

spasmodic.  Her  pulse  was  weak.  At  11. 45  a.  m.  her  respiration  was  68.  At  9.30  p.m. 
her  temperature  was  105.3°  F.,  respiration  24,  and  pulse  120,  but  weak.  The  animal 
was  given  subcutaneously  3  drops  of  fluid  extract  of  digitalis  in  6  c.  c.  of  whisky. 
During  the  day  there  had  been  very  little  change  in  her  condition.  She  lay  in  a 
coma,  from  which  she  did  not  rouse  herself  except  occasionally  to  shake  the  flies 
from  her  ears.  Her  position  had  been  changed  from  time  to  time  by  the  attendants. 
She  was  found  dead  on  the  morning  of  July  22. 

At  the  autopsy  the  venous  blood  vessels  were  found  congested  and  the  lungs  were 
congested,  as  were  the  liver  and  kidneys.  There  was  considerable  inflammation  of 
the  walls  of  the  fourth  stomach  and  of  the  whole  length  of  the  intestines.  Sections 
of  the  kidney  showed  that  the  capillaries  were  much  congested ,  and  there  was  some 
degeneration  of  the  tubule  walls.  Sections  of  the  liver  showed  acute  congestion,  and 
the  same  condition  was  noticed  in  the  sections  of  the  lung. 

Sheep  No.  197. — This  animal  (Table  I,  section  G)  was  a  ewe  2  years  old,  lent  by 
Mr.  Ole  Birk eland  on  May  9,  1913.  An  unsuccessful  attempt  was  made  to  feed  Zyga- 
denus  venenosus  tops  to  her  on  May  12. 

On  May  26,  at  11.25  a.  m.,  she  was  drenched  with  178  grams  of  Zygadenus  venenosus 
tops  suspended  in  water.  These  plants  were  collected  on  May  23.  At  11.40  a.  m. 
she  was  frothing  at  the  mouth.  At  11.45  a.  m.  she  was  given  a  drench  of  1  gram  of 
diuretin  and  0.455  gram  of  caffein  citrate.  At  11.50  a.  m.  she  was  vomiting,  and  when 
observed  at  12  m.  the  vomiting  was  continuing.  At  12.05  p.  m.  her  respiration  was 
getting  irregular  and  deeper.  At  12.30  p.  m.  her  respiration  was  extremely  fast  and 
she  was  panting.  At  this  time  she  was  violently  nauseated  and  threw  herself  down 
two  or  three  times  and  then  jerked  about  in  a  spasmodic  manner.  At  12.40  p.  m., 
being  extremely  nauseated  she  was  trying  to  vomit,  throwing  herself  down,  and  the 
spasmodic  movements  were  followed  by  quick,  panting  respiration.  At  12.45  p.  m. 
her  respiration  was  about  200.  She  showed  weakness  in  her  legs.  At  1.15  p.  m.  she 
repeated  the  spasmodic  movements  which  had  been  noticed  at  12.30  and  12.40  p.  m., 
evidently  struggling  to  get  breath.  She  threw  her  head  from  side-  to  side  and  ran  the 
length  of  the  corral,  throwing  herself  upon  the  ground  and  rising  again  as  though 
having  a  fit.  The  mucous  membranes  of  the  mouth  were  cyanotic.  These  move- 
ments were  repeated  a  little  later.  At  1.30  p.  HI.  she  was  given  a  dose  of  5  c.  c.  of  gin. 
Another  struggle  for  breath 'followed,  and  it  was  noted  after  this  struggle  that  her 
heart  action  was  very  rapid  and  strong.  The  beat  was  audible  to  the  observers. 
Five  c.  c.  more  of  gin  were  given  subcutaneously.  At  1.36  p.  m.  she  was  lying  upon 
her  side.  Her  respiration  was  160.  At  1.40  p.  m.  she  had  another  struggle  for  breath, 
throwing  herself  about  violently,  even  throwing  herself  over  upon  her  back.  These 
struggles  were  repeated  at  1.49  and  at  1.53  p.  m.  The  mucous  membrane  of  the 
mouth  at  both  times  was  very  markedly  cyanotic.  At  1.55  p.  m.  she  was  given  5  c.  c. 
of  gin.  At  this  time  she  was  still  strong.enough  to  get  on  her  feet.  She  was  urinating 
freely.  At  1.59  p.  m.  she  passed  through  another  spasmodic  attempt  to  breathe. 
At  2.02  p.  m.  her  pulse  was  about  200.  At  2.06  p.  m.  there  was  a  spasmodic  struggle 
for  breath.  At  2.10  p.  m.  the  animal  was  breathing  with  very  great  difficulty.  Am- 
monia was  used  to  stimulate  her  respiration.  Her  pulse  was  130.  At  2.45  p.  m.  she  had 
great  difficulty  in  respiration,  but  at  this  time  it  was  not  accompanied  by  a  spasmodic 
struggle.  At  3.06  p.  m.  she  had  another  spasmodic  struggle,  and  ammonia  was  used 
as  a  stimulant.  At  3.30  p.  m.  her  respiration  some  of  the  time  was  very  rapid,  becom- 
ing as  high  as  200  per  minute.  Then  it  slowed  down  and  became  labored.  On  the 
whole  the  animal  at  this  time  seemed  somewhat  better.  At  3.39  p.  m.  she  made  a 
struggle  to  get  upon  her  feet  but  was  unable  to  do  so.  Her  respiration  at  this  time 
was  variable  and  very  labored,  the  breathing  being  followed  by  quick,  panting  efforts. 
At  4.10  p.  m.  her  respiration  nearly  stopped.  She  was  stimulated  with  ammonia. 
At  4.15  p.  m.  ammonia  was  again  used.  At  4.45  p.  m.  her  respiration  was  132.  At 


24  BULLETIN   125,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

5.19  p.  m.  the  animal  was  upon  her  side.  Her  respiration  was  labored,  but  seemed 
somewhat  stronger.  Her  condition  remained  very  nearly  the  same  until  6  p.  m. 
At  6.30  p.  m.  she  was  found  dead. 

The  autopsy  showed  that  the  lungs  were  slightly  congested ;  the  inner  walls  of  the 
ileum  were  congested  and  the  venous  blood  vessels,  generally  speaking,  were  full. 
It  was  evident  that  death  had  occurred  from  respiratory  paralysis. 

The  detailed  report  of  the  examination  of  the  internal  organs  by  Dr.  Mohler,  of  the 
Bureau  of  Animal  Industry,  is  as  follows: 

Kidney  (cortex  and  medulla). — Many  of  the  intertubular  capillaries  in  the  laby- 
rinth of  the  cortex  and  some  Malpighian  bodies  show  a  marked  distention,  but  not 
sufficiently  pronounced  to  be  called  congestion.  There  is  also  a  general  distention  of 
many  of  the  convoluted  tubules  and  the  interstices  between  the  capsule  of  Bowman 
and  glomeruli  with  a  serous,  oedematous  exudate.  This  latter  has  distended  the 
tubules  and  compressed  the  renal  epithelial  cells,  many  of  which,  having  become 
atrophic  from  pressure,  disintegrated  and  desquamated  into  the  lumen  of  the  tube. 
While  these  changes  are  quite  marked  in  the  convoluted  tubules,  the  oedema,  des- 
quamation,  and  degeneration  are  absent  in  the  straight  portions  of  the  uriniferous 
tubules  of  the  medulla.  The  distention  of  the  capillaries,  however,  is  present  even 
in  the  medulla.  No  interstitial  alterations  are  present. 

Lung. — The  characteristic  lesion  is  the  intense  congestion  of  the  entire  organ,  the 
presence  of  small  lobular  areas  of  consolidation,  and  occasional  minute  oedematous 
areas.  The  larger  pulmonary  and  bronchial  vessels  are  all  overdistended,  but  the 
interfundibular  capillaries  show  not  only  overdistention  but  also  diapedesis  and 
outwandering  of  the  leucocytes.  No  such  capillary  hemorrhages  or  poollike  accumu- 
lations of  the  blood  can  be  seen  in  this  lung  as  were  previously  observed  in  lung  716. 
The  bronchial  tubes  and  the  smaller  bronchi  are  unaltered .  There  is  no  peribronchitis 
present,  although  the  bronchial  blood  vessels  have  all  participated  in  the  distention 
of  the  other  vessels  of  the  lung. 

Kidney. — No  acute  inflammatory  changes  present.  Evidences  of  a  slight  subacute 
catarrhal  nephritis  accompanied  by  mild  degenerative  changes  in  the  renal  cells  in 
the  cortical  portion  of  the  kidney.  No  interstitial  changes  present. 

Liver. — Moderate  amount  of  physiological  fatty  infiltration  and  a  slight  congestion  of 
the  intralobular  capillaries  between  the  liver  cords,  but  no  diapedesis  of  red  blood 
cells  or  outwandering  of  leucocytes.  The  hepatic  cells  proper  show  a  slight  amount 
of  cloudy  swelling  in  isolated  lobules.  No  interstitial  changes  present. 

Ileum. — Shows  a  slight  increase  in  the  adenoid  tissue  in  the  niucosa  and  slight 
fullness  of  the  blood  vessels  in  the  submucosa.  There  is,  however,  no  congestion, 
desquamation,  or  degeneration  present. 

SYMPTOMS  IN  SHEEP  OBSERVED  AT  THE  GREYCLIFF  STATION. 

The  very  large  number  of  cases  of  illness  and  death  observed  at 
the  Greycliff  station  furnished  an  opportunity  for  a  fairly  complete 
picture  of  the  symptoms  produced  by  Zygadenus  poisoning.  The 
symptoms  were  noted  in  detail,  and  the  description  that  follows  is 
drawn  from  a  summarized  statement  formulated  from  these  notes. 

SALIVATION. 

Generally  salivation,  or  frothing  at  the  mouth,  was  the  first 
noticeable  symptom  and  continued  through  the  acute  period  of  the 
illness.  It  was  not  invariably  present;  sometimes  it  did  not  appear, 
especially  in  the  fed  cases.  It  was  seen  in  nearly  all  the  drenched 


ZYGADENUS,    OR   DEATH    CAM  AS.  25 

cases,  and  was  rarely  absent  when  the  attack  was  acute.  The  saliva- 
tion was  in  many  cases  accompanied  by  grinding  of  the  teeth.  Plate 
IV,  figure  1,  of  sheep  No.  160,  and  Plate  IV,  figure  2,  of  sheep  No.  192, 
illustrate  this  stage  of  the  illness. 

NAUSEA. 

Nausea  was  very  pronounced  in  nearly  all  cases,  and  frequently 
resulted  in  violent  vomiting,  this  vomiting,  like  the  salivation,  being 
largely  confined  to  the  acute  stage  of  the  illness. 

PULSE. 

Routine  observations  upon  the  pulse  were  made  in  a  large  number 
of  cases.  The  rate  of  the  pulse  is,  of  course,  very  variable  under- 
normal  conditions.  When  taken  before  the  experimental  feeding  it 
varied  from  52  to  144,  although  in  most  cases  it  was  between  60  and 
100.  Generally  speaking,  when  the  intoxication  was  not  acute  there 
was  'very  little  change  from  what  would  be  expected  in  normal 
variations  either  in  the  rate  or  character  of  the  pulse.  In  the  severer 
cases,  especially  in  those  that  ended  fatally,  the  rate  was  from  125 
to  200.  While  in  three  cases  of  sheep  not  under  the  influence  of  a 
toxic  substance  the  pulse  was  144,  this  condition  is  unusual;  and 
in  a  general  way  it  seems  to  be  true  that  if  the  rate  runs  much  above 
130  a  fatal  termination  of  the  illness  is  likely  to  follow.  In  the 
severe  cases  the  pulse  was  weak  and  sometimes  intermittent. 

TEMPERATURE. 

Temperature  observations  were  made  in  detail  in  a  large  number 
of  cases.  It  was  considered  necessary  to  get  the  average  of  a  con- 
siderable number,  inasmuch  as  there  is  in  sheep  quite  a  range  of 
variability  under  normal  conditions  and  also  a  considerable  difference 
in  individuals.  The  extreme  range  of  temperature  was  from  97.4° 
to  105.7°  F.  From  the  cases  of  1914,  64  records  were  made.  Of 
these,  8  showed  no  marked  change,  14  exhibited  an  increase,  and  42 
a  decrease,  and  the  decrease  ordinarily  was  not  very  great  but  in 
some  few  cases  was  down  to  between  97°  and  98°  F.  It  is  evident 
that,  in  general,  intoxication  by  Zygadenus  is  accompanied  by  depres- 
sion of  temperature.  In  some  few  cases,  ih  which  there  were  no 
other  symptoms  of  poisoning,  a  lowering  of  temperature  was  noticed; 
this,  however,  was  not  sufficiently  general  so  that  it  could  be  con- 
sidered diagnostic  in  the  absence  of  other  symptoms.  Curves  are 
given  (figs.  1  and  2)  of  sheep  282  and  291.  These,  it  should  be  stated, 
are  not  average  cases,  but  they  may  be  considered  typical  of  cases 
in  which  the  lowering  of  temperature  is  more  marked. 


26 


BULLETIN   125,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


RESPIRATION. 


The  rate  of  respiration  had  an  extremely  wide  range  of  variation. 
Quite  uniformly  in  the  acute  stages  of  the  poisoning,  the  rate  was 
very  rapid,  running  in  some  cases  as  high  as  250  per  minute.  After 
this  period  the  rate  was  very  much  reduced,  falling  to  normal  or  below, 


/OO 


97 


>R  M. 


FIG.  1.— Curve  of  temperature  of  sheep  No.  282. 


and  the  animal  sometimes  lay  for  hours  breathing  most  of  the  tune 
in  a  slow  and  labored  fashion.  This  period  of  comparative  quiet  might 
be  interrupted,  sometimes  frequently,  by  times  of  rapid  breathing, 
accompanied  by  panting  and  followed  quickly  by  a  very  slow  rate. 
Sometimes,  in  severe  cases,  there  were  tunes  when  the  animal  threw 


/OS 


/oo 


^J* 


\ 


i  FIG.  2.— Curve  of  temperature  of  sheep  No.  291 

itself  about  violently,  fighting  for  oxygen.  This  condition  lasted  for 
perhaps  two  or  three  minutes  and  was  succeeded  by  a  period  of  quiet, 
which  was  soon  broken  by  another  struggle.  During  these  struggles 
the  mucous  membranes  of  the.  mouth  were  frequently  cyanotic. 
The  struggles  were  spasmodic,  and  when  authors  state  that  poisoned 
animals  have  spasms  or  convulsions,  it  is  to  be  presumed  that  they 


ZYGADENUS,    OK  DEATH    CAMAS. 


27 


refer  to  this  condition.  It  should  be  noted,  however,  that  in  the 
cases  observed  at  the  Greycliff  station  there  was  no  indication  of  any 
special  tonic  or  clonic  contraction  of  the  muscles;  the  violent  move- 
ments of  the  animals  were  simply  those  caused  by  distress  from 
dyspnoea. 

Figure  3  gives  the  curve  of  respiration  for  sheep  No.  174  and  may 
be  considered  typical  of  the  average  fatal  case.  The  sheep  was 
drenched  at  12  o'clock 
noon  and  died  at  1 1 . 1 5 
p.m.  The  respiratory 
rate  rose  to  200  be- 
tween 2  and  3  o'clock, 
when  the  animal  had 
one  of  the  spasmodic 
struggles  for  breath. 
It  then  fell  to  9  and 
remained  low,  with 
comparatively  slight 
variations,  until  the 
time  of  death. 

Figure  4  gives  the 
curve  of  respiration 
of  sheep  No.  160,  a 
prolonged  case.  This 
animal  was  drenched 
with  Zygadenus  at 
11.25  a.  m.,  July  19, 
and  died  during  the 
nightofJuly21.  The 
respiration  almost  im- 
mediately after  the 


JSO 


//o 


70 


dose  was  given  ran 
up  to  200  and  during 
the  afternoon  varied 

between   60    and    168.  FIG.  3.-Curve  of  respiration  of  sheep  No.  174. 

In  the  evening  it  fell,  and  after  that  time  the  maximum  noticed  was 
68,  but  most  of  the  time  it  was  near  20  or  30. 

MUSCULAR  WEAKNESS. 

In  all  cases  of  any  severity  muscular  weakness  was  noticeable. 
Early  in  the  illness  the  animals  staggered,  and  in  the  more  serious 
cases  not  only  could  not  rise,  but  lay  flat  upon  the  ground.  This 
weakness  was  most  pronounced  in  the  forelegs.  Plate  V,  figure  1, 
shows  this  condition  of  weakness  in  the  forelegs  in  sheep  No.  162, 
while  Plate  V,  figure  2,  shows  the  same  animal  down.  Plate  VI, 


28 


BULLETIN   125,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 


figure  1,  shows  sheep  No.  174  when  down  and  very  sick.     This  picture 
was  taken  just  before  a  spasmodic  struggle  for  breath. 

In  many  cases  in  which  the  animals  were  strong  enough  to  remain 
on  their  feet,  the  gait  was  peculiarly  stiff  legged.  Both  fore  and  hind 
limbs  were  affected,  but  the  condition  was  most  pronounced  in  the 
hind  legs.  Sometimes  the  hind  legs  were  moved  less  readily,  approxi- 
mating, perhaps,  the  condition  noticed  by  other  writers  in  laboratory 
experiments.  These  symptoms  were  especially  noticeable  in  the 
cases  in  which  the  animals  were  fed  and  were  not  very  sick. 


FIG.  4. — Curve  of  respiration  of  sheep  No.  160. 
TREMBLING  AND  HEIGHTENED  REFLEXES. 

The  fed  cases  generally  exhibited  trembling  and  a  sensitiveness  to 
sudden  noises  or  movements.  A  blow  upon  the  corral  fence  was  fol- 
lowed by  a  sudden  start  on  the  part  of  the  animal,  or  a  light  blow  upon 
the  animal  was  followed  by  a  quick  reflex  movement.  This  con- 
dition was  not  noticed  in  the  drenched  cases  and  seems  to  be  more 
characteristic  of  prolonged  illnesses.  As  stated  before,  this  symp- 
tom of  heightened  reflexes  had  been  noted  by  both  Chesnut  and 
Hunt. 

COMA. 

While,  as  already  noted  under  the  head  of  respiration,  death 
resulted  from  respiratory  failure  and  was  frequently  preceded  by 
spasmodic  attacks  of  dyspnoea,  there  were  other  cases  in  which  the 
animals  lay  quietly  hour  after  hour,  and  sometimes  even  for  days, 
with  labored  breathing,  in  a  condition  of  coma  which  ended  in 


Bui.  125,  U.  S.  Oept.  of  Agriculture. 


PLATE  V 


I 


FIG.  1.— SHEEP  No.  168  AT  1.30  P.  M.,  SHOWING  WEAKNESS  IN  FORELEGS. 


FIG.  2.— SHEEP  No.  1  68  AT  5.45  P.  M..  WHEN  UNABLE  TO  RISE. 


Bui.  125,  U.  S.  Dept.  of  Agriculture. 


PLATE  VI 


FIG.  1.— SHEEP  No.  174,  DOWN  AND  IN  BAD  CONDITION.    PHOTOGRAPHED  JUST 
BEFORE  A  SPASMODIC  STRUGGLE  FOR  BREATH. 


FIG.  2.— SHEEP  No.  161,  DOWN  ALMOST  Two  HOURS  AND  UNABLE  TO  RISE. 


ZYGADENUS,    OR   DEATH    CAMAS.  29 

death  without  any  exhibition  of  spasms.  Plate  VI,  figure  2,  shows 
sheep  No.  161  in  this  condition  of  coma.  Sheep  that  are  poisoned 
on  the  range  are  more  apt  to  be  in  this  condition  of  prolonged  coma 
than  to  show  the  more  violent  symptoms  of  dyspnoea  exhibited  by 
animals  that  are  drenched  or  forcibly  fed. 

SYMPTOMS  IN  HORSES  AND  CATTLE. 

No  results  on  horses  were  reached  in  the  experimental  work  at 
Greycliff.  From  conversations  with  stockmen  who  have  had  experi- 
ence with  horses  poisoned  by  Zygadenus,  it  appears  that,  in  general, 
the  symptoms  resemble  those  exhibited  in  sheep. 

In  the  cases  of  the  two  head  of  cattle  which  showed  symptoms,  the 
experiment  was  carried  only  to  the  point  of  proving  the  toxic  effect 
of  the  plant,  and  no  attempt  was  made  to  get  a  complete  symptomatic 
picture.  The  animals  became  uneasy,  displayed  heightened  reflexes, 
and  one  dragged  the  hind  legs  slightly.  So  far  as  they  went,  the 
symptoms  were  like  those  observed  in  sheep. 

AUTOPSIES. 

Autopsies  were  made  on  four  cases  in  1912,  six  in  1913,  and  seven 
in  1914.  Of  the  cases  in  1913,  sheep  No.  186,  while  showing  distinct 
symptoms  of  Zygadenus  poisoning,  died  as  the  result  of  the  admin- 
istration of  morphin. 

The  appearances  presented  by  these  animals  at  the  autopsies  were 
quite  uniform,  though  not  alike  in  all  details.  In  six  cases  there 
was  epicarditis.  In  nearly  all,  the  inner  wall  of  the  ileum  was 
hypersemic  or  congested,  and  in  all  but  one  the  lungs  were  congested. 
The  kidneys  were  congested  and  more  or  less  degenerated  in  most 
cases.  Generally  the  heart  was  in  systole,  the  contraction  being 
most  marked  in  the  left  ventricle. 

Generally  speaking,  then,  the  post-mortem  appearances  may  be 
stated  as  including  inflammation  of  the  inner  wall  of  the  ileum  and 
occasionally  of  the  fourth  stomach  and  large  intestines,  the  heart 
in  systole,  congestion  of  the  lungs,  and  congestion  and  more  or  less 
degeneration  of  the  kidneys.  Possibly  the  condition  of  epicarditis 
may  be  considered  typical,  although  it  was  not  noted  in  all  the 
cases. 

The  preserved  material  from  the  autopsies  was  examined  by  Dr. 
Mohler,  and  the  following  summarized  statement  of  the  pathological 
findings  and  the  inferences  to  be  drawn  has  been  furnished  by  him : 

The  most  conspicuous  phenomenon  shown  in  all  six  cases  was  the  high  capillary 
blood  pressure,  manifested  principally  in  those  organs  which  eliminated  the  active 
principle  of  the  ingested  substance,  that  is,  kidneys,  lungs,  and  liver,  being  also  shown 
to  a  less  extent  in  the  intestine. 

In  the  kidney  the  changes  in  the  capillary  varix  were  fullness  to  overdistention, 
which  was  accompanied  by  outwandering  of  leucocytes,  diapedesis  of  the  red  blood 


30 


BULLETIN    125,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 


corpuscles,  and  all  the  phenomena  of  a  congestion  or  an  acute  cr  subacute  inflamma- 
tion. Occasional  ruptures  of  the  capillary  vessels  were  noted,  forming  poollike  capil- 
lary hemorrhages. 

The  distention  of  the  capillaries  in  some  instances  had  brought  about  cloudy  swell- 
ing, or  the  early  stage  of  degeneration  of  the  renal  epithelium,  which  in  some  instances 
had  become  desquamated.  The  supporting  or  interstitial  tissue  was  not  affected. 

In  the  lung  the  high  capillary  pressure  is  even  more  manifest  than  in  the  kidney, 
owing  to  the  presence  of  a  greater  number  of  capillaries.  The  variations  were  from 
moderate  fullness  to  overdistention,  followed  by  inflammation  in  the  more  acute 
cases,  resulting  in  localized  areas  of  oedema  where  the  serum  had  oozed  out  and  filled 
one  or  more  lobules  of  the  lung. 

In  spite  of  the  fact  that  the  fullness,  congestion,  and  inflammation  were  more  marked 
in  the  lung  than  in  the  kidneys,  the  degenerative  changes  and  the  desquamation  of 
the  pulmonary  epithelium  were  less  evident  and  not  as  frequent,  owing  to  the  greater 
resistance  of  the  pulmonary  cells.  While  no  interstitial  changes  were  present  in 
the  kidney,  slight  interstitial  changes  in  the  lungs  were  present  in  the  peribronchial 
areas  in  some  of  the  cases.  In  others,  the  interstitial  changes  were  also  present  in 
the  visceral  pleura. 

In  the  liver  the  vascular  changes  were  either  entirely  absent  or  so  slight  as  not  to 
deserve  any  mention,  but  the  epithelial  changes  were  quite  marked,  owing  to  the 
more  delicate  composition  of  the  cytoplasm.  The  absence  of  vascular  changes  indi- 
cates that  the  elimination  by  this  organ  is  but  very  slight  and  that  the  metabolic 
function  is  quite  able  to  take  care  of  any  of  the  irritant  products  that  may  have  reached 
the  liver. 

In  the  intestine  the  vascular  changes  are  likewise  very  slight. 

TOXIC  AND  LETHAL  DOSE  OF  ZYGADENUS  VENENOSUS  FOR  SHEEP. 

The  very  large  number  of  feeding  experiments  with  sheep  at  Grey- 
cliff  made  it  possible  to  determine  the  toxic  and  lethal  dose  with  con- 
siderable accuracy.  Inasmuch  as  very  little  has  been  known  in 
regard  to  the  toxic  dose  of  Zygadenus  for  sheep,  the  results  of  these 
cases  are  especially  interesting.  Table  II  summarizes  the  nonfatal 
cases,  showing  their  number  and  the  quantities  of  the  plant  neces- 
sary to  produce  illness. 

TABLE  II. — Nonfatal  cases  of  poisoning  of  sheep  by  Zygadenus  venenosus  at  Grey  cliff, 
Mont.,  in  1912,  1913,  and  1914. 


Feeding  experiments. 

Number 

Quantity  i 

ased  per  100 
animal. 

pounds  of 

Maximum. 

Minimum. 

Average. 

Season  of  1912: 
Drenched  with  leaves,  stems,  and  fruit  

2 

Pounds. 
1.324 

Pounds. 
0.79 

Pounds. 
1.057 

Drenched  with  stems  and  leaves  

1 

.33 

Drenched  with  stems,  fruit,  and  some  leaves 

2 

.771 

.33 

.55 

Drenched  with  fruit 

5 

.264 

.141 

.228 

Season  of  1913: 
Fed  on  leaves  .  . 

4 

2.1 

.893 

1.607 

Drenched  with  leaves  

8 

.747 

.385 

.5746 

Drenched  with  bulbs  

3 

.612 

.517 

.5746 

Drenched  with  leaves  and  buds 

-  l 

.555 

Drenched  with  buds  and  flowers 

1 

.389 

Fed  on  leaves  and  flowers  . 

G 

4.6 

1.728 

2.  7513 

Drenched  with  leaves  and  flowers 

2 

.496 

.495 

.4955 

Fed  on  leaves,  flowers,  and  fruit  

2 

7.188 

3.155 

5.  1715 

Fed  on  seed  heads 

1 

5.597 

5.597 

Fed  on  seeds  .  .  . 

3 

.241 

.092 

.1613 

ZYGADENUS,    OR  DEATH    CAMAS. 


31 


TABLE  II. — Nonfatal  cases  of  poisoning  of  sheep  by  Zygadenus  venenosus  atGreycliff, 
Mont.,  in  1912,  1913,  and  1914— Continued. 


Feeding  experiments. 

Number 
of  cases. 

Quantity  used  per  100  pounds  of 

animal. 

Maximum. 

Minimum. 

Average. 

Season  of  1914: 
Forced  feeding  of  leaves            

2 
2 

1 

8 
4 

1 

9 

4 
1 

1 

3 

6 

18 
2 

1 
2 

Pounds. 
0.662 
.499 

Pounds. 
0.661 
.550 

Pounds. 
0.6615 
.5245 
1.643 

.5495 
1.789 
1.912 

1.712 

.851 
1.543 

1.432 

1.69 
1.175 
.859 
.7415 
.540 
.153 

Forced  feeding  of  leaves  and  some  young  buds 

Fed  on  leaves,  some  young  buds,  and  a  few  flowers..  . 
Forced  feeding  of  leaves,  stems,  flowers,  and  buds  — 
Material  collected  near  the  station  

.622 
1.983 

.495 
1.436 

Cabin  Corral  collections                     

Fed  on  leaves  stems  flowers  and  buds 

Forced  feeding  of  leaves,  stems,  and  flowers  (Cabin 
Corral  collections) 

2.756 
.992 

.992 
.757 

Forced  feeding  of  leaves,  stems,  flowers,  and  young 
fruit 

Forced  feeding  of  very  young  seed  heads  

Forced  feeding  of  seed  heads,  some  fully  developed 

Forced  feeding  of  half-developed  seed  heads  (Cabin 
Corral  collections)  

1.754 
1.323 

.994 
.741 

1.543 

.881 
.440 
.740 

Forced  feeding  of  nearly  developed  seed  heads 

Forced  feeding  of  fully  developed  seed  heads  

Forced  feeding  of  ripening  seed  heads  

Forced  feeding  of  pods  with  saeds  removed 

Forced  feeding  of  seeds                  

.197 

.110 

Table  III  summarizes  the  fatal  cases  in  the  three  seasons. 

TABLE  III. — Fatal  cases  of  poisoning  of  sheep  by  Zygadenus  venenosus  at  Greycliff, 
Mont.,  1912,  1913,  and  1914. 


Feeding  experiments. 

Number 
of  cases. 

Quantity  used  per  100  pounds  of 
animal. 

Maximum. 

Minimum. 

Average. 

Season  of  1912: 
Drenched  with  fruit  

3 

1 
4 
1 

1 

2 
3 

Pounds. 
0.853 

Pounds. 
0.299 

Pounds. 
0.571 

1.397 
.537 
.550. 

.544 
.936 
.213 

Season  of  1913: 
Fed  on  leaves  

Drenched  with  leaves 

.746 

.384 

Drenched  with  leaves  and  flowers  

Season  of  1914: 
Forced  feeding  of  leaves  stems,  and  flowers 

Forced  feeding  of  fully  developed  seed  heads  
Forced  feeding  of  seeds 

.991 
.220 

.882 
.199 

As  these  feedings  were  carried  on  during  the  season  as  long  as  the 
plants  could  be  obtained  and  as  it  was  practically  impossible  to  have 
any  considerable  number  of  cases  at  one  time,  it  is  evident  that  the 
number  of  cases  under  any  given  set  of  conditions  must  have  been 
small.  As  a  matter  of  fact,  none  of  the  cases  of  1912  were  strictly 
comparable  with  those  of  1913.  Consequently,  the  actual  averages 
of  dosage  were  based  on  a  comparatively  small  number  of  cases. 

In  1914,  there  was  a  much  larger  number  of  cases,  and  some  stages 
of  the  plant  were  fed  upon  which  no  experiments  were  made  in  the 
preceding  years.  Even  in  this  year,  however,  there  were  only  a  few 
cases  in  which  the  experiments  were  under  identical  conditions. 


32  BULLETIN  125,  U.   S.  DEPARTMENT  OF  AGRICULTURE. 

In  the  compilation  of  Tables  II  and  III  some  of  the  cases  have  been 
excluded.  In  Table  II  all  cases  in  which  the  remedy  given  was 
clearly  effective  were  excluded,  for  some  of  these  received  what  would 
have  been  a  lethal  dose  had  it  not  been  for  the  remedy.  In  Table  III 
•cases  were  excluded  which  were  known  to  have  received  much  more 
than  a  lethal  dose.  The  uniformity  of  dosage  in  1914  is  explained  by 
the  fact  that  the  preceding  work  had  shown  clearly  that  the  toxic 
dose  was  not  far  from  0.5  pound,  and  the  experiments  were  made  on 
this  basis.  It  should  be  noted,  too,  that  most  of  the  work  of  the 
summer  of  1914  was  with  reference  to  the  experimental  use  of  reme- 
dies, so  that  the  quantity  of  the  plant  administered  was  estimated 
to  be  sufficient  not  simply  to  produce  symptoms,  but  to  make  the 
animal  very  sick,  in  order  to  get  a  fair  test  of  the  remedy.  Hence, 
the  average  figures  for  the  toxic  dose  will  be  rather  high. 

The  "forced  feeding"  cases  of  1914  can  be  fairly  compared  with  the 
"drenched"  cases  of  1912  and  1913,  as  the  difference  between  the 
two  methods  is  mainly  in  the  fact  that  in  forced  feeding  no  water  is 
used  while  in  drenching  considerable  water  is  necessary  as  a  vehicle 
for  the  weed. 

The  age  of  the  animal  played  a  comparatively  small  part  in  these 
experiments,  as  all  the  animals  were  mature,  most  of  them  being  2 
years  old  or  older. 

It  will  be  noticed  that  when  the  plant  was  given  in  the  form  of  a 
drench  or  by  forced  feeding,  the  dosage,  as  would  be  expected,  was 
considerably  less  than  when  it  was  given  with  food.  An  examination 
of  the  complete  table  of  feeding  (Table  I)  shows  also  very  clearly  that 
the  size  of  the  dose  varied  inversely  with  the  time  during  which  the 
material  was  eaten.  In  a  large  number  of  cases  in  which  the  plant 
was  given  with  food,  the  feeding  extended  over  two  or  more  days. 
In  those  cases  the  dosage  was  considerably  greater  than  when  the 
material  was  fed  in  a  single  day.  It  may  be  assumed  that  if  the 
same  quantity  of  the  plant  which  was  received  in  a  drench  could 
have  been  fed  within  a  short  period  of  time,  the  effect  would  have 
been  the  same. 

The  average  dose  which  produced  illness  when  administered  in  the 
form  of  a  drench  or  by  forced  feeding  was  practically  the  same  for 
all  parts  of  the  plant  except  the  pods  and  seed.  It  appears  that  the 
plants  are  less  toxic  at  the  time  when  the  pods  are  forming,  which  may 
be  due,  in  part  at  least,  to  the  diminished  toxicity  of  the  leaves  as  they 
dry  up.  It  is  not  clear,  however,  from  this  work,  that  the  leaves  lose 
any  appreciable  amount  of  toxicity,  and  the  more  probable  explana- 
tion is  that  the  pods  at  this  time  are  only  slightly  toxic.  In  the  single 
experiment  of  feeding  pods  without  seeds,  the  dosage  was  about  like 
that  of  other  parts  of  the  plants,  but  it  is  probable  from  the  detailed 
history  of  this  experiment  that  this  is  not  a  fair  representative  of  such 
cases. 


ZYGADENUS,    OR  DEATH    CAMAS.  33 

The  seeds  are  very  much  more  poisonous  than  any  other  part  of  the 
plant.  Heyl,  Loy,  Knight,  and  Prien  (1912,  p.  17)  give  the  results  of 
determinations  of  alkaloids-  in  different  parts  of  the  plant.  Their 
statement  is  obscure  and  contradictory,  but  apparently  they  reach 
the  conclusion  that  the  bulbs  and  leaves  contain  approximately  the 
same  quantity  of  the  alkaloid,  the  roots  much  less,  and  the  flowers 
about  twice  as  much  as  the  bulbs  and  leaves.  This  compares  very 
well  with  the  results  of  the  experimental  feeding  at  Greycliff,  except 
that  it  did  not  appear  that  the  flowers  were  more  toxic  than  other 
parts  of  the  plant. 

Table  II  gives  the  maximum  and  minimum  dosage,  and  it  will 
be  noticed  that  there  is  a  considerable  range  of  variation  between 
these  two.  The  individual  peculiarities  of  the  animal  in  cases  of 
poisoning  doubtless  must  be  taken  into  account,  and  the  detailed 
table  of  the  experiments  shows  that  in  some  cases  a  larger  quantity 
of  plant  than  that  which  this  table  indicates  to  be  toxic  may  be 
administered  without  effect.  In  most  of  the  cases,  however,  where 
the  larger  amount  was  used,  the  feeding  was  distributed  over  a 
longer  time. 

In  general,  the  experiments  seem  to  indicate  that  when  any  part 
of  the  plant  except  the  seed  is  used  the  toxic  dose  varies  from  1..6 
pounds  per  hundredweight  of  animal  to  5.6  pounds,  this  wide  range 
of  variation  being  accounted  for  by  the  more  or  less  extended  time 
of  feeding.  In  the  drenching  and  forced-feeding  experiments,  more 
uniform  results  were  reached,  showing  that  the  toxic  dose  of  all  parts 
of  the  plant,  except  the  seed,  is  not  far  from  0.5  pound  per  hundred- 
weight of  animal. 

There  is  considerable  difference  in  the  items  of  the  summarized 
tables  in  the  exactness  of  the  averages,  and  some  explanation  is 
necessary  to  indicate  their  actual  value. 

In  the  feeding  of  leaves  in  1914,  there  were  three  cases,  two 
becoming  sick.  The  third  case  received  0.661  pound  without  symp- 
toms, the  same  quantity  that  was  received  by  No.  282,  which  became 
sick.  It  seems  probable,  then,  that  the  average  figure  0.6615  must 
be  pretty  close  to  the  toxic  limit.  In  the  feeding  of  "  leaves  and  some 
young  buds"  in  1914,  while  the  minimum  of  sick  cases  received  0.499 
pound,  another  animal  received  0.551  pound  without  ill  effect;  it  is 
evident  that  the  toxic  limit  must  be  not  far  from  0.5  pound.  In  the 
feeding  of  eight  cases  on  "leaves,  stems,  flowers,  and  buds/'  with 
material  collected  near  the  station,  the  toxic  limit  was  practically  the 
same  as  in  the  preceding  cases.  A  perusal  of  Table  II  shows  that 
during  the  growth  of  the  seed  heads  the  toxicity  was  reduced  and 
that  the  fully  developed  seed  heads  were  somewhat  less  toxic  than 
the  plant  in  the  earlier  stages. 


34  BULLETIN  125,  U.    S.   DEPARTMENT   OF  AGRICULTURE. 

In  the  two  cases  of  forced  feeding  of  seeds  in  1914  the  average  toxic 
dose  was  0.153  pound;  inasmuch  as  the  animal  receiving  the  maxi- 
mum amount  was  very  sick,  the  actual  toxic  limit  must  be  consid- 
ered to  be  close  to  the  minimum  figure  of  0.11  pound.  It  will  be 
noticed  that  the  cases  of  feeding  of  seeds  in  1913  had  practically  the 
same  average  dose  as  the  cases  of  forced  feeding  in  1914;  this  is 
accounted  for  by  the  fact  that  these  animals  ate  the  seed  in  such  a 
short  time  that  the  results  were  similar  to  those  from  forced  feeding. 

It  is  interesting  to  note  in  Table  III  that  the  lethal  dose  is  only 
slightly  larger  than  the  toxic  dose. 

In  transferring  these  results  to  the  probable  dosage  when  sheep 
are  range  fed,  the  feeding  habits  of  the  sheep  must  be  taken  into 
consideration.  In  the  corrals  the  sheep  do  not,  as  a  rule,  eat  as 
readily  as  when  on  the  range.  When  the  sheep  in  a  band  are  grazing 
together,  both  imitation  and  jealousy  affect  the  quantity  of  any  plant 
which  a  sheep  eats  in  a  given  time;  so  it  is  reasonable  to  suppose 
that  if  feed  is  short  and  Zygadenus  fairly  abundant,  sheep  may  eat 
much  more  in  a  short  time  than  they  would  under  corral  conditions. 
Under  such  circumstances,  the  dosage  might  approximate  that  of 
the  drenching  experiments.  Therefore,  it  appears  probable  that 
animals  feeding  on  the  range  might,  because  of  the  more  rapid  eating, 
be  poisoned  with  much  less  than  when  in  corrals. 

EXPERIMENTS  WITH  HORSES  AND  CATTLE. 

Three  experiments  were  made  of  feeding  Zygadenus  to  a  horse, 
as  shown  in  Table  I  (section  D),  Z.  venenosus  being  used  in  two  tests 
and  Z.  elegans  in  one.  The  smallest  quantity  fed  in  these  experi- 
ments was  12.1  pounds  per  1,000  pounds  of  weight,  and  the  largest 
was  15  pounds.  In  each  instance  the  feeding  was  extended  through 
several  days,  and  the  feeding  of  15  pounds  extended  through  6  days. 
If  the  quantity  necessary  to  poison  a  horse  should  be  in  the  same 
proportion  to  its  weight  as  that  required  to  poison  a  sheep,  it  would 
be,  according  to  our  dosage,  at  least  between  11  and  12  pounds,  and 
probably  much  more.  It  may  be  presumed,  therefore,  that  in  these 
cases  the  amount  fed  was  not  sufficient  to  produce  toxic  effects. 
There  is,  however,  abundance  of  evidence  that  horses  are  poisoned 
by  Zygadenus,  although  not  ordinarily  with  fatal  results. 

Section  C  of  Table  I  shows  the  results  of  feeding  Zygadenus 
venenosus  to  three  cattle.  Two  of  these  animals,  both  of  which 
received  leaves  and  flowers,  showed  symptoms  of  poisoning,  one 
on  58  pounds  per  1,000  pounds  of  weight  and  the  other  on  46.5 
pounds  per  1,000  pounds  of  weight.  In  these  cattle,  therefore, 
the  average  toxic  dose  was  52.25  pounds,  which  was  fed  in  an  average 
of  6£  days.  This  compares  fairly  well  with  the  results  reached  with 


ZYGADENUS,   OR  DEATH   CAMAS.  35 

sheep  and  would  indicate  that  the  toxic  dose  for  cattle,  computed 
in  terms  of  the  weight  of  the  animal,  does  not  differ  materially 
from  the  toxic  dose  for  sheep. 

COMPARATIVE  TOXICITY  OF  DIFFERENT  SPECIES  OF  ZYGADENUS. 

In  the  course  of  the  experiments,  four  species  of  Zygadenus  were 
used,  Z.  venenosus,  Z.  elegans,  Z.  paniculatus,  and  Z.  color adensisj  by 
far  the  greater  part  of  the  work  being  done  with  Z.  venenosus.  The 
number  of  experiments  with  Z.  elegans  and  Z.  paniculatus  was  very 
small,  and  the  material,  especially  in  the  case  of  Z.  paniculatus,  had 
been  shipped  a  long  distance,  so  that  there  was  some  question  of  the 
water  content  of  the  plant.  Apparently,  however,  Z.  elegans  and  Z. 
paniculatus  do  not  differ  materially  in  toxicity  from  Z.  venenosus. 
Z.  coloradensis,  however,  produced  no  toxic  effects  whatever  with 
the  exception  of  slight  symptoms  in  one  sheep,  although  the  plant 
was  fed  in  quantities  several  times  as  great  as  the  toxic  dose  of  Z. 
venenosus. 

It  is  evident  that  in  the  feeding  of  cattle  with  Zygadenus  coloraden- 
sis at  Mount  Carbon  in  1909,  the  results  of  which  are  given  in  Table  I, 
the  quantities  fed  were  too  small  to  produce  results,  even  if  the 
plants  were  as  poisonous  as  Z.  venenosus.  In  the  experiment  of 
1910,  however,  a  Jarge  quantity  was  fed,  and  sufficiently  large 
quantities  in  single  days  to  produce  symptoms  of  poisoning  if  the 
plant  were  as  toxic  as  Z.  venenosus. 

In  this  connection  it  should  be  added  that  Dr.  C.  L.  Alsberg  made 
a  laboratory  examination  of  the  Colorado  plants  and  found  in  them 
a  very  small  quantity  of  alkaloid.  It  would  appear,  then,  that  the 
form  which  is  identified  by  some  botanists  as  Z.  coloradensis  contains 
the  same  toxic  substance  as  the  other  form,  but  that  this  substance 
is  present  in  so  small  a  quantity  that  it  is  unlikely  that  it  ever 
produces  toxic  effects  on  domestic  animals.  While  it  is  not  in  the 
province  of  this  paper  to  discuss  the  systematic  relations  of  plants,  it 
may  be  suggested  that  this  difference  of  toxicity  between  Z.  elegans 
and  Z.  coloradensis  may  indicate  a  valid  specific  distinction  between 
these  two  forms  which  are  so  closely  related  that  by  some  botanists 
they  are  considered  identical. 

DOES  TOXICITY  VARY  WITH  LOCALITY? 

The  collections  of  Zygadenus  venenosus  with  which  experiments 
were  made  were  obtained  at  the  "Station"  (by  which  is  understood 
the  region  within  a  radius  of  2  miles  of  the  station),  at  an  elevation 
of  about  4,050  feet;  at  "GreycliftY'  2i  to  3  miles  distant  from  the 
station,  at  an  elevation  of  about  3,920  feet;  and  at  "Cabin  Corral" 
and  "George  Hughes's  "  (locations  from  4  to  7  miles  from  the  station), 
at  an  elevation  of  something  over  5,000  feet.  Material  of  this  species 


36  BULLETIN   125,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

was  also  used  from  Avery,  Cal.,  collected  at  an  elevation  of  3,500  feet. 
The  material  of  Z.  elegans  was  from  two  localities,  from  near  Red 
Lodge,  Mont.,  at  an  elevation  between  5,500  and  6,000  feet,  and  from 
the  Fishlake  National  Forest,  Utah,  at  an  elevation  of  something 
over  9,000  feet.  The  Z.  paniculatus  material  was  collected  near 
Ephraim,  Utah,  at  an  elevation  between  5,500  and  6,000  feet.  All 
the  Z.  coloradensis  material  was  collected  within  4  or  5  miles  of  the 
Mount  Carbon  station,  at  an  elevation  of  something  over  10,000  feet. 

As  has  been  stated  already,  the  lack  of  toxic  properties  in  Zygadenus 
coloradensis  is  assumed  to  be  characteristic  of  the  species.  The  experi- 
ments with  Z.  elegans  and  Z.  paniculatus  were  few  in  number,  and 
too  much  importance  must  not  be  attached  to  the  results.  Appar- 
ently, however,  not  only  did  they  have,  practically,  the  same  toxicity 
as  the  Z.  venenosus  collected  near  the  station,  but  there  was  no  evident 
difference  between  the  Z.  elegans  of  Montana  and  that  collected  in 
Utah.  The  Z.  venenosus,  collected  in  California  gave  the  same  results 
as  that  produced  by  material  from  the  neighborhood  of  the  Greycliff 
station. 

An  entirely  unexplained  variation  in  toxicity  was  exhibited  by 
material  collected  at  Cabin  Corral,  about  5  miles  from  the  station  and 
at  a  greater  elevation  of  about  a  thousand  feet.  When  Table  II 
was  being  compiled,  it  was  noticed  that  the  cases  receiving  "forced 
feeding  of  leaves  stems,  flowers,  and  buds"  fell  into  two  distinct 
divisions,  one  with  an  average  dosage  of  0.5495  pound  and  the  other 
with  an  average  of  1.789  pounds.  This  difference  was  so  marked 
that  the  two  sets  were  separated  in  the  summary.  In  searching  for 
some  possible  explanation  of  this  difference,  it  was  found  that  all 
the  cases  with  the  larger  dosage  were  treated  with  material  collected 
at  Cabin  Corral.  Note  was  then  made  of  the  other  items  in  this  table 
which  were  collected  in  this  locality,  and  a  glance  at  the  table  will 
show  that  in  the  other  cases  the  Cabin-Corral  material  showed  much 
less  toxicity.  It  has  been  entirely  impossible  to  explain  this  difference. 
The  number  of  cases  would  seem  to  make  it  certain  that  this  result 
was  not  due  to  an  error  of  experimentation.  There  are  no  local 
conditions  to  account  for  it.  The  George  Hughes  place,  at  which 
collections  were  made  giving  the  same  results  as  those  produced  by 
the  station  material,  is  situated  at  about  the  same  distance  from  the 
camp  as  Cabin  Corral,  at  about  the  same  elevation,  and  it  has  the 
same  soil  conditions.  The  question  of  the  correlation  of  variation 
in  toxicity  with  changes  in  altitude  was  raised,  but  the  experiments  do 
not  indicate  any  such  relation.  The  fact  that  the  Cabin-Corral  mate- 
rial was  less  toxic  is  nevertheless  substantiated,  and  it  would  appear 
that  while  Zygadenus  venenosusf  Z.  elegansy  and  Z.  paniculatus  have 
ordinarily  the  same  degree  of  toxicity  wherever  grown,  there  is  a  pos- 
sibility of  marked  variation. 


ZYGADENUS,   OR  DEATH   CAMAS.  37 

EFFECT    OF   REPEATED   FEEDING   IN    PRODUCING   IMMUNITY    OR   IN- 
CREASED SUSCEPTIBILITY. 

During  the  course  of  the  experimental  work  at  Greycliff  a  number 
of  sheep  were  treated  with  Zygadenus  several  times  during  the 
same  season.  It  was  important  to  decide  whether  a  sheep  after 
having  been  poisoned  once  was  more  or  less  likely  to  be  affected  a 
second  time.  A  careful  analysis  of  the  results  showed  that  no  effect 
cither  of  immunity  or  of  increased  susceptibility  was  produced. 
The  fact  that  an  animal  had  suffered  from  poisoning  once  neither 
lessened  the  effect  of  another  dose,  nor,  on  the  other  hand,  was  the 
sheep  any  more  likely  to  suffer  from  a  second  experience. 

REMEDIES. 

Because  of  the  heavy  losses  of  sheep  from  Zygadenus  poisoning 
it  was  deemed  important  to  investigate  thoroughly  the  possibility 
of  finding  some  remedial  measures  to  reduce  the  number  of  deaths. 
To  this  end  a  large  number  of  experiments  were  made,  as  can  be  seen 
by  an  examination  of  the  table  giving  the  summarized  account  of  the 
work. 

It  has  been  shown  by  Hunt  that  the  poisonous  principle  of  Zyga- 
denus is  excreted  in  the  urine,  and  this  has  been  verified  by  the 
authors  in  the  cases  of  some  of  the  sheep  used  in  the  Greycliff  experi- 
ments. Hunt  concluded  that  the  logical  remedy  is  some  diuretic 
which  will  insure  excretion  rapid  enough  to  prevent  serious  effects 
from  the  poisoning,  and  his  experiments  seem  to  substantiate  this 
position.  He  also  advised  the  use  of  permanganate  of  potash 
administered  per  os  to  destroy  the  alkaloid  in  the  stomach. 

The  experimental  work  on  remedies  in  1912  was  based  upon  these 
conclusions  of  Hunt.  Later,  a  number  of  remedies  were  used  in  the 
hope  that  some  method  might  be  found  sufficiently  simple  to  be  used 
under  range  conditions.  This  work  was  carried  on  for  three  summers 
in  order  to  get  the  average  of  a  considerable  number  of  cases,  and 
a  brief  statement  of  the  results  of  the  more  important  experiments 
follows. 

CAFFEIN  AND  DIURETIN. 

The  conclusions  reached  by  Hunt  led  to  a  series  of  experiments 
with  caffein.  In  1912,  caffein  sodiobenzoate  was  administered  to 
five  animals  subcutaneously;  in  two  of  these  cases  potassium  perman- 
ganate was  also  used,  and  in  one  tannic  acid.  It  was  evident  that 
by  the  use  of  this  drug  the  excretion  of  urine  was  increased,  but  the 
observers  could  not  see  that  any  marked  improvement  followed  in 
the  condition  of  the  animals.  In  the  summer  of  1913,  diuretin  and 
caffein  citrate  were  given  per  os  in  four  cases,  of  which  one  died  and 
three  recovered.  In  these  cases,  as  in  those  of  the  preceding  year, 


38  BULLETIN   125,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

there  was  no  evidence  of  any  good  result.  All  these  experiments  had 
been  with  single  doses.  In  1914  two  animals  were  treated,  one 
with  two  doses  of  10  grains  each  of  caffein  sodiobenzoate  adminis- 
tered subcutaneously,  and  one  with  three  doses  of  5  grains  each. 
One  of  these  animals  died  and  one  recovered,  but  in  neither  case 
could  it  be  seen  that  the  remedy  was  advantageous.  It  seemed  to 
be  clear  that  while  caffein  might  be  considered  a  logical  remedy  it 
failed  in  practical  application. 

STRYCHNIN. 

Although  the  work  of  Hunt  quite  clearly  indicated  that  strychnin 
was  not  beneficial,  it  seemed  best  to  try  a  few  experiments  to  see 
whether,  by  its  stimulating  effect,  it  might  not  aid  in  relieving  the 
depression  of  the  animals.  Six  cases  were  treated  by  subcutaneous 
injections.  In  two  of  these  cases  eserin  was  also  used,  and  in  one 
case  gin.  There  was  an  apparently  beneficial  effect  in  one  case,  but 
a  study  of  all  fails  to  show  any  good  results  which  could  be  fairly 
considered  as  due  to  strychnin. 

ESERIN,  EPSOM  SALTS,  LINSEED  OIL. 

With  the  idea  that  relief  might  be  brought  about  by  an  increase  in 
intestinal  elimination,  eserin  was  administered  subcutaneously,  and 
Epsom  salts  and  linseed  oil  per  os;  no  reduction  of  toxic  symptoms 
could  be  seen. 

CHARCOAL. 

Dr.  Sollman  suggested  to  the  writers  that  charcoal,  by  adsorption, 
might  be  beneficial.  Three  experiments  were  made  with  this,  in 
one  case  combined  with  linseed  oil.  No  beneficial  results  followed. 

WHISKY  AND  DIGITALIS. 

In  some  cases  of  extreme  depression  whisky  seemed  to  have  an 
effect  in  bridging  over  a  period  when  death  might  otherwise  have 
followed.  The  same  thing  is  true  of  digit alis,  which  in  one  or  two 
cases  may  have  saved  the  life  of  the  patient.  Neither  drug,  however, 
had  any  marked  effect.  It  can  only  be  said  that  if  the  symptoms  of 
the  animal  are  carefully  watched,  times  will  be  found  when  whisky 
or  digitalis  may  be  administered  advantageously.  Inasmuch  as  the 
life  of  the  individual  sheep  is  of  small  importance,  these  remedies  are 
of  little  practical  use. 

POTASSIUM  PERMANGANATE. 

Especial  interest  attaches  to  the  experiments  with  potassium 
permanganate,  since  it  is  the  remedy  that  has  been  most  commonly 
recommended  for  plant  poisoning.  The  dosage  advised  for  a  mature 
sheep  has  been  5  to  9  grains.  This  was  used  at  first  in  the  experi- 
mental work,  and  when  no  beneficial  results  appeared  it  was  increased 


OR  DEATH    CAMAS.  39 

to  30  grains,  but  still  with  no  evidence  of  a  reduction  of  the  toxic 
effect.  In  two  cases,  15  grains  were  introduced  directly  into  the 
rumen  with  no  better  results. 

Because  of  this  lack  of  success  it  was  deemed  best  to  try  mixing 
the  permanganate  with  the  Zygadenus  before  administration  to  see 
if  the  alkaloid  would  be  destroyed  in  vitro.  On  May  19,  1913,  two 
sheep  of  equal  weight,  Nos.  184  and  191,  were  each  drenched  with 
0.586  pound  of  Zygadenus  venenosus  in  water.  In  the  dose  given  to 
No.  191  there  were  dissolved  7J  grains  of  potassium  permanganate 
and  7J  grains  of  aluminum  sulphate.  Both  animals  were  sick,  and 
there  was  no  recognizable  difference  in  the  degree  of  illness.  The 
experiment  tended  to  show  that  the  administration  of  the  potassium 
permanganate  was  without  any  definite  effect  upon  the  toxicity  of  the 
plant,  but  a  similar  experiment  on  July  11,  1914,  on  sheep  No.  253 
showed  quite  clearly  that  the  dosage  of  the  former  experiment  was 
insufficient.  In  this  case  0.441  pound 'of  seed  heads  of  Z.  venenosus 
was  mixed  in  water  with  15  grains  of  potassium  permanganate  and 
15  grains  of  aluminum  sulphate  and  the  mixture  allowed  to  stand  for 
20  minutes  before  being  administered.  The  sheep  displayed  no 
symptoms  of  poisoning,  although  other  cases  of  the  same  date 
receiving  the  same  quantity  of  Zygadenus,  with  no  remedy,  showed 
distinct  symptoms.  It  seemed  clear  that  a  sufficient  quantity  of 
permanganate  will  diminish  the  toxicity  of  the  plant,  when  mixed 
with  it  before  administration.  When  given  after  symptoms  of  poison- 
ing are  exhibited,  however,  the  remedy  is  of  no  value.  This,  too,  has 
been  demonstrated  by  practical  experience  upon  the  range.  Potas- 
sium permanganate  has  been  used  by  many  sheep  owners  in  Montana, 
and  it  is  the  almost  universal  testimony  that  it  is  worthless. 

TANNIC  ACID. 

Sheep  No.  206,  on  June  4,  1913,  was  drenched  with  0.43  pound  of 
Zygadenus  tops,  including  leaves  and  flowers.  To  this  drench  were 
added  three  grams  of  tannic  acid.  The  animal  showed  no  signs  of 
illness.  On  May  29  a  sheep  was  made  sick  on  0.389  pound,  and  on 
May  30  one  was  made  sick  on  0.385  pound  and  one  died  on  0.384 
pound.  It  seems  fair  to  presume,  therefore,  that  the  tannic  acid  had 
been  of  benefit  to  sheep  No.  206. 

Sheep  No.  210,  on  June  6,  1913,  was  drenched  with  0.496  pound  of 
leaves  and  flowers  of  Zygadenus  venenosus  to  which  3  grams  of  tannic 
acid  had  been  added.  On  the  same  date  sheep  No.  209  received  0.495 
pound  of  the  same  material,  but  without  the  tannic  acid.  Both 
animals  were  sick  and  recovered,  but  it  was  the  impression  of  the 
observers  that  sheep  No.  210  was  not  as  sick  as  sheep  No.  209. 

On  June  7, 1913,  sheep  Nos.  212  and  213  were  each  drenched  with 
0.55  pound  of  leaves  and  flowers  of  Zygadenus  venenosus.  In  the 


40  BULLETIN   125,   U.    S.   DEPARTMENT   OF   AGRICULTURE. 

drench  given  to  No.  212  were  included  4  grams  of  tannic  acid.  This 
sheep  had  no  symptoms  of  illness,  while  No.  213  died  1  hour  and  17  min- 
utes after  the  administration  of  the  drench.  These  two  sheep  were  of 
very  nearly  equal  weight  and  the  dose  was  the  same  (0.55  pound)  per 
hundredweight  of  animal.  There  was  every  reason  to  expect  similar 
results  except  for  the  effect  of  the  tannic  acid.  Difference  of  indi- 
vidual susceptibility  would  seem  to  be  eliminated  in  this  instance,  in 
which  one  animal  died  and  the  other  showed  no  symptoms  of  poisoning. 

During  the  season  of  1913,  four  animals  which  had  been  fed  on 
Zygadenus  venenosus  were  given  doses  of  tannic  acid  after  toxic 
symptoms  were  well  developed.  All  of  these  animals  recovered. 
These  cases,  however,  were  not  connected  up  with  control  cases, 
and  it  is  possible  that  all  would  have  recovered  without  any  remedial 
aid. 

The  general  result  of  all  the  experiments  in  1913  with  tannic  acid 
indicated  that  it  can  be  used  with  beneficial  results.  The  experiments 
seemed  also  to  indicate  very  clearly  that,  in  vitro,  the  tannic  acid  was 
much  more  effective  than  potassium  permaganate  as  an  antidote  for 
the  Zygadenus  alkaloid. 

In  1914,  a  large  number  of  cases  were  treated  with  tannic  &cid, 
in  order  to  try  it  out  thoroughly.  In  most  of  these  experiments  one 
or  more  control  animals  were  used.  Where  the  tannic  acid  was 
administered  in  a  single  dose,  in  19  cases,  there  were  only  two  deaths; 
in  most  of  these  cases,  however,  the  Zygadenus  was  not  given  in  a 
quantity  necessarily  fatal. 

A  study  of  the  cases  in  which  there  was  a  control  shows  apparently 
beneficial  results  in  some  instances.  For  example,  sheep  Nos.  249 
and  251  received  the  same  quantity  of  Zygadenus  on  July  9;  No.  249 
died,  while  No.  251,  which  received  a  dose  of  tannic  acid,  lived. 

Sheep  Nos.  229  and  235  were  fed  the  same  quantity  of  Zygadenus 
on  June  3.  No.  229  was  treated  with  tannic  acid  and  was  not  so  sick 
as  No.  235.  On  the  other  hand,  Nos.  239  and  256  were  fed  on  June 
16  with  the  same  quantity,  and  No.  239,  which  received  the  tannic 
acid,  had  more  marked  symptoms  than  No.  256.  Sheep  Nos.  269, 
255,  and  282  were  fed  the  same  quantity  of  Zygadenus  on  June  15 
and  June  16.  Tannic  acid  was  administered  to  Nos.  269  and  282; 
both  of  these  animals  were  sick,  while  No.  255  exhibited  no  symp- 
toms. A  consideration  of  all  these  cases  shows  that  tannic  acid  in 
single  doses  can  not  be  considered  an  effective  remedy,  although 
under  favorable  conditions  some  cases  may  be  benefited. 

SODIUM   BICARBONATE. 

It  was  suggested  by  Mr.  O.  F.  Black  that,  inasmuch  as  alkaloids 
are,  to  a  large  extent,  insoluble  in  an  alkaline  solution,  sodium  bicar- 
bonate might  serve  to  prevent  the  solution  and  absorption  of  the 


OR  DEATH   CAMAS.  41 

poisonous  principle  of  Zygadenus  and  thus  prove  valuable  as  a  medic- 
inal remedy.  This  was  used  only  in  repeated  doses,  and  the  results 
will  be  discussed  under  the  next  head. 

REPEATED  DOSES  OF  TANNIC  ACID  AND  SODIUM  BICARBONATE. . 

Inasmuch  as  tannic  acid  is  a  recognized  remedial  agent  for  poison- 
ing by  alkaloids,  it  seemed  strange  that  so  little  benefit  followed 
its  use.  In  seeking  for  an  explanation,  it  occurred  to  the  writers 
that  it  might  be  accounted  for  by  the  fact  that,  because  of  the  char- 
acter of  a  ruminant's  stomachs,  the  remedy  does  not  actually  come  in 
contact  with  any  considerable  quantity  of  the  poisonous  substance. 
The  first  stomach  of  a  ruminant  always  contains  a  large  quantity  of 
material.  When  an  animal  feeds  upon  a  poisonous  plant,  the  ma- 
terial taken  up  goes  to  the  first  stomach;  some  of  this,  after  macera- 
tion, proceeds  to  the  third  and  fourth  stomachs,  while  another  part 
goes  on  only  after  rumination.  If  the  remedy  is  given  in  the  form  of  a 
drench,  it  will  be  distributed  in  all  the  stomachs,  although  ordinarily 
the  larger  part  of  the  drench  goes  directly  to  the  third  and  fourth 
stomachs.  That  part  of  the  drench  which  goes  to  the  fourth  stomach, 
we  can  assume,  takes  effect  on  the  alkaloid  which  has  arrived  at  that 
part  of  the  digestive  canal.  The  portion  of  the  drench  which  stops 
in  the  first  stomach  meets  a  mass  of  organic  matter,  in  which  it  is 
lost;  there  is  no  reason  to  think  that  any  antidote  for  an  alkaloid 
will  have  any  selective  effect,  so  as  to  attack  the  Zygadenus  alkaloid 
rather  than  the  multitude  of  other  substances  in  the  stomach  with 
which  it  can  unite.  The  only  hope  of  destroying  the  alkaloid  under 
such  circumstances  would  be  by  flooding  the  first  stomach  with  the 
antidote,  and  that  is  practically  impossible.  So  even  when  the  anti- 
dote is  introduced  by  a  canula  directly  into  the  first  stomach,  it  would 
be  impracticable  to  use  a  quantity  sufficient  to  produce  any  marked 
effect. 

On  the  other  hand,  inasmuch  as  no  absorption  takes  place  in  the 
stomachs,  if  the  antidote  could  meet  the  poisonous  material  as  it 
passes  through  the  fourth  stomach  good  results  might  be  expected. 
On  the  basis  of  this  conclusion,  it  seemed  best  to  the  writers  to  try 
the  effect  of  antidotes  repeated  at  frequent  intervals;  it  was  thought 
that  if  the  antidote  could  reach  the  fourth  stomach  frequently 
enough  to  catch  the  alkaloid  as  it  passed  from  the  first  stomach  and 
render  it  more  or  less  innocuous  before  passing  into  the  intestine,  the 
remedy  might  be  distinctly  beneficial. 

Four  experiments  of  this  character  were  conducted  with  tannic 
acid,  all  with  controls,  which  received  no  remedy  but  were  fed  with 
the  same  quantity  of  Zygadenus.  The  tannic  acid  was  given  in  doses 
of  1  and  2  grams,  repeated  at  intervals  varying  from  10  to  30  min- 
utes, or  longer  in  some  cases,  at  the  latter  part  of  the  experiment. 


42  BULLETIN   125,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

The  total  time  of  treatment  varied  from  4  to  7J  hours,  and  the  total 
quantity  of  tannic  acid  given  varied  from  14  to  16  grams.  The 
doses  and  intervals  were  as  follows : 

Sheep  No.  263:  9  doses,  1  gram  each,  once  in  10  minutes;  2  doses,  1  gram  each,  once 
in  30  minutes;  1  dose,  1  gram,  in  20  minutes;  2  doses,  1  gram  each,  once  in  30  minutes. 
Total,  14  grams. 

Sheep  No.  216:  7  doses,  2  grams  each,  once  in  30  minutes.     Total,  14  grams. 

Sheep  No.  267:  5  doses,  1  gram  each,  once  in  10  minutes;  3  doses,  1  gram  each,  once 
in  15  minutes;  8  doses,  1  gram  each,  once  in  30  minutes.  Total,  16  grams. 

Sheep  No.  291:  3  doses,  2  grams  each,  once  in  30  minutes;  1  dose,  2  grams,  in  60 
minutes;  1  dose,  2  grams,  in  30  minutes;  2  doses,  2  grams  each,  once  in  60  minutes; 
1  dose,  2  grams,  in  3  hours.  Total,  16  grams. 

All  these  animals  recovered  and  were  not  as  sick  as  the  controls, 
Nos.  269  and  294.  Sheep  No.  291  suffered  more  than  the  others, 
but  the  tannic  acid  in  this  case  was  administered  later  in  the  illness, 
after  a  course  of  small  doses  of  Epsom  salts  had  failed  to  produce 
any  effect.  All  these  animals  and  the  controls  were  given  Zygadenus 
collected  on  the  same  date.  The  experiments  were  considered  to 
prove  conclusively  that  repeated  doses  of  tannic  acid  are  beneficial. 

A  similar  set  of  experiments  was  conducted  with  sodium  bicarbon- 
ate. Seven  animals  were  used,  and  all,  with  one  exception,  were  fed 
Zygadenus  material  collected  on  the  same  date,  and  in  the  excep- 
tional case  the  material  was  collected  only  a  few  days  later.  Doses 
of  sodium  bicarbonate  of  2  and  4  grams  were  given  at  intervals  vary- 
ing from  15  to  60  minutes.  The  total  time  of  treatment  was  from 
2J  to  5  hours,  and  the  total  amount  of  sodium  carbonate  given  varied 
from  20  to  48  grams.  The  doses  and  intervals  were  as  follows: 

Sheep  No.  246:  10  doses,  4  grams  each,  once  in  30  minutes.     Total,  40  grams. 

Sheep  No.  259:  8  doses,  4  grams  each,  once  in  15  minutes;  4  doses,  4  grams  each, 
once  in  30  minutes.  Total,  48  grams. 

Sheep  No.  264:  6  doses,  4  grams  each,  once  in  60  minutes.    Total,  24  grams. 

Sheep  No.  292:  10  doses,  4  grams  each,  once  in  30  minutes.    Total,  40  grams. 

Sheep  No.  293:  4  doses,  4  grams  each,  once  in  30  minutes;  2  doses,  2  grams  each, 
once  in  30  minutes.  Total,  20  grams. 

Sheep  No.  277:  5  doses,  4  grams  each,  once  in  30  minutes;  2  doses,  2  grams  each, 
once  in  30  minutes;  1  dose,  2  grams,  after  1£  hours.  Total,  26  grams. 

Sheep  No.  240:  3  doses,  8  grams  each,  once  in  60  minutes;  2  doses,  4  grams  each, 
once  in  60  minutes.  Total,  32  grams. 

Of  these  animals  all  recovered  but  one,  No.  264.  This  sheep  re- 
ceived a  total  of  24  grams,  given  at  hour  intervals.  No.  240  also 
received  the  remedy  at  hour  intervals  and  recovered  very  slowly, 
being  unable  to  stand  on  the  morning  after  the  poisonous  dose  had 
been  given.  All  the  other  cases,  except  No.  277,  recovered  rather 
quickly.  No.  277  was  as  slow  as  No.  240,  although  the  doses  of 
sodium  bicarbonate  were  given  frequently,  and  the  total  amount  was 


ZYGADENUS,   OR  DEATH   CAM  AS.  43 

greater  than  that  given  to  No.  264  and  to  No.  293,  which  recovered. 
If  we  exclude  No.  277,  it  would  appear  clear  that  sodium  carbonate 
given  in  sufficiently  frequent  doses  is  distinctly  beneficial.  The  Zyga- 
denus  in  the  case  of  No.  277  was  given  in  three  doses,  and  it  is  pos- 
sible that  there  was  some  accumulative  effect,  which  may  explain  in 
part  the  slow  recovery. 

The  general  conclusion  from  the  experiments  with  sodium  bicar- 
bonate is  that  if  the  remedy  is  given  at  frequent  intervals  it  will  prove 
distinctly  beneficial.  The  dose  should  be  4  grams,  and  this  should 
be  repeated  as  often  as  every  30  minutes. 

These  experiments  with  repeated  doses  of  tannic  acid  and  sodium 
bicarbonate  were  interesting  from  a  theoretical  standpoint  and  indi- 
cate a  line  of  treatment  which  can  be  used  successfully  with  valuable 
animals.  It  is  evident,  however,  that  remedies  used  in  this  way  can 
not  be  recommended  for  the  ordinary  band  of  sheep,  for  the  expense 
of  the  treatment  would  be  greater  than  the  value  of  the  animals. 

No  experiments  of  repeated  doses  were  made  with  potassium  per- 
manganate; but  it  is  probable  that  it  could  be  used  successfully, 
although  the  general  trend  of  the  experimental  work  is  to  indicate 
that  the  potassium  permanganate  is  not,  as  a  remedy,  so  efficient  as 
tannic  acid  and  sodhim  bicarbonate. 

BLEEDING. 

It  is  customary  among  sheep  herders  to  bleed  sheep  poisoned  by 
Zygadenus,  the  favorite  place  being  the  angular  artery  and  vein  of 
the  eye.  Although  there  seems  to  be  no  logical  reason  for  this  prac- 
tice, it  seemed  wise  to  try  it,  and  three  sheep  were  treated  in  this 
way;  two  of  the  three  died,  and  no  beneficial  result  appeared  in  any 
of  the  cases. 

METHODS  OF  PREVENTING  LOSSES. 

The  most  obvious  thing  to  do  is,  of  course,  to  keep  the  animals 
from  eating  the  plant.  With  this  end  in  view,  it  is  important  that 
all  herders  should  be  taught  to  recognize  Zygadenus.  When  the 
plant  is  in  flower  this  is  not  at  all  difficult,  but  it  has  been  a  matter  of 
surprise  to  find  to  what  extent,  among  the  herders  and  sheep  owners, 
the  plant  is  not  known,  even  at  this  stage.  Before  flowering,  its 
grasslike  leaves  are  not  so  easily  recognized,  but  there  is  no  reason 
why  a  fairly  intelligent  man  should  not  be  taught  to  know  it  even  then. 
If  one  knows  the  plant  in  the  preflowering  and  flowering  stages,  he 
will  readily  recognize  it  in  the  later  dried-up  condition,  when,  it  will 
be  remembered,  it  is  fully  as  dangerous  as  earlier  in  the  season. 

When  the  plant  is  recognized  care  should  be  taken  that  the  sheep 
do  not  have  an  opportunity  to  eat  any  large  quantity  of  it.  If 
it  be  necessary  to  drive  the  sheep  over  a  patch  of  Zygadenus,  the 
herder  should  take  the  precaution  to  have  the  band  well  fed  before 


44  BULLETIN  125,  U.   S.   DEPARTMENT   OF   AGRICULTURE. 

making  the  drive.  If  hungry  sheep  come  upon  a  thick  growth  of  Zyga- 
denus, some  of  them,  in  their  haste  to  satisfy  their  hunger,  are  almost 
certain  to  become  poisoned,  while  if  already  well  fed  they  are  likely 
to  choose  their  food  with  more  care  and  to  eat  less  of  the  Zygadenus. 

Special  care  should  be  used  early  in  the  season,  not  because  the 
plant  is  more  poisonous  at  that  time,  but  because,  on  account  of  the 
dry  condition  of  other  forage,  it  is  more  likely  to  be  eaten.  Later 
in  the  season  sheep  are  less  likely  to  eat  a  large  quantity,  because  of 
the  greater  abundance  of  other  food.  As  a  matter  of  fact,  most  of  the 
cases  of  extensive  poisoning  have  occurred  before  the  flowering  of 
the  plant. 

If  sheep  become  poisoned,  they  should  be  kept  as  quiet  as  possible. 
Any  attempt  to  make  them  move  about  is  likely  to  have  disastrous 
results. 

So  far  as  remedies  are  concerned,  none  has  been  found  so  far  that 
gives  much  promise  of  being  really  useful.  The  experimental  work 
at  Greycliff  shows  that  repeated  doses  of  tannic  acid  or  sodium 
bicarbonate  will  aid  in  recovery,  but  this  method  of  treatment  is  not 
practically  possible  for  animals  upon  the  range. 

GENERAL  SUMMARY. 

Zygadenus  grows  abundantly  on  many  of  the  stock  ranges  of  the 
West  and  is  one  of  the  most  important  sources  of  loss  to  sheepmen. 
Apparently  all  species  of  Zygadenus  are  poisonous.  The  plants  are 
poisonous  through  the  whole  season  of  their  growth,  but  the  tops  are 
somewhat  more  poisonous  at  the  time  of  flowering.  The  toxicity  of 
the  bulbs  and  tops  is  about  the  same,  while  the  seeds  are  much  more 
toxic  than  other  parts  of  the  plant.  Cases  of  poisoning  are  more 
likely  to  occur  before  the  maturity  of  the  plant,  because  at  that  time 
other  forage  is  scanty. 

The  toxic  dose  varies  according  to  the  conditions  of  feeding.  In 
drenched  animals  it  may  be  put  at  about  one-half  a  pound  for  an 
animal  weighing  a  hundred  pounds.  In  fed  animals  it  varied  from 
1.6  pounds  to  5.6  pounds. 

The  poisonous  principle  is  an  alkaloid  or  alkaloids  allied  to  veratrin 
and  cevadin. 

Sheep,  cattle,  and  horses  are  poisoned  by  the  plant,  but  the  fatali- 
ties are  almost  entirely  confined  to  sheep. 

The  principal  symptoms  are  salivation,  nausea,  muscular  weakness, 
coma,  and  sometimes  attacks  of  dyspnoea. 

To  prevent  losses,  it  is  important  to  recognize  the  plant  and  avoid 
grazing  upon  it.  If  animals  become  sick  they  should  be  kept  quiet, 
and  under  this  treatment  many  will  recover.  There  is  no  satisfac- 
tory medical  remedy. 


LITERATURE  CITED. 

BRITTON,  N.  L.,  and  BROWN,  ADDISON. 

1913.  Illustrated  Flora  of  the  Northern  United  States,  Canada,  and  the  British 

Possessions  .  .  .  ed.  2,  v.  1,  New  York,  p.  490-491. 
CHESNUT,  V.  K. 

1902.   Plants  used  by  the  Indians  of  Mendocino  County,  California.     Contri- 
butions, U.  S.  National  Herbarium,  v.  7,  p.  ^21-322,  327. 
-  and  WILCOX,  E.  V. 

1901.  The  stock-poisoning  plants  of  Montana;  a  preliminary  report.     U.  S.  De- 
partment of  Agriculture,  Division  of  Botany,  Bulletin  26,  p.  51-64,  pi.  1. 
COLLIER,  PETER. 

1882.  Proximate  analysis  of  Zygadenus  paniculatus.     Report,  [U.  S.]  Commis- 
sioner of  Agriculture,  1881/82,  p.  547-548. 
COULTER,  J.  M. 

[1909.]  New  Manual  of  Botany  of  the  Central  Rocky  Mountains  .  .  .  rev.  by 

Aven  Nelson.     New  York,  p.  118-119. 
COVILLE,  F.  V. 

1897.  Notes  on  the  plants  used  by  the  Klamath  Indians  of  Oregon.     Contribu- 
tions, U.  S.  National  Herbarium,  v.  5,  no.  2,  p.  93. 
GRAY,  ASA. 

1848.  Melanthacearum  Americae  Septentrionalis  revisio.     Annals,   Lyceum  of 
Natural  History,  New  York,  v.  4,  p.  124. 


[1908.]  Gray's  New  Manual  of  Botany,  ed.  7,  rev.  by  B.  L.  Robinson  and  M.  L. 

Fernald.     New  York,  Cincinnati,  p.  284. 
HELLER,  A.  A. 

1909.  The  death  camus.     Muhlenbergia,  v.  5,  no.  3,  p.  50-52. 
HEYL,  F.  W.,  and  HEFNER,  F.  E. 

1913.  Some  constituents  of  the  leaves  of  Zygadenus  intermedius.  III.  Journal, 
American  Chemical  Society,  v.  35,  no.  6,  p.  803-811. 

-  and  LOY,  S.  K. 

[1912.]  Zygadenine.  The  crystalline  alkaloid  of  Zygadenus  intermedius.  Sec- 
ond paper.  Wyoming  Agricultural  Experiment  Station,  22d  Annual  Report, 
1911/12,  p.  51-57,  2  fig. 


1913.  Zygadenine.  The  crystallin  alkaloid  of  Zygadenus  intermedius.  Journal, 
American  Chemical  Society,  v.  35,  no.  3,  p.  258-262,  2  fig.  See  also  Wyoming 
Agricultural  Experiment  Station,  Bulletin  101. 

—  LOY,  S.  K.,  KNIGHT,  H.  G.,  and  PRIEN,  O.  L. 

1912.  The  chemical  examination  of  death  camas.  Wyoming  Agricultural  Experi- 
ment Station,  Bulletin  94,  31  p.,  3  fig. 

—  and  RAIFORD,  CHARLES. 


46  BULLETIN   125,   U.    S.   DEPARTMENT    OF   AGRICULTURE. 

HILLMAN,  F.  H. 

1893.  A  poisonous  plant.     Nevada  Agricultural  Experiment  Station,  Newspaper 
Bulletin  5,  1  p.,  1  fig. 


1897a.  A    dangerous  range   plant.     Nevada  Agricultural   Experiment   Station, 
Newspaper  Bulletin  21,  1  p.,  1  fig. 


18976.  Nevada  weeds.     III.  Nevada  and  other  weed  seeds.     Nevada   Agricul- 
tural Experiment  Station,  Bulletin  38,  p.  114-116,  fig.  116-117. 

HOOKER,  W.  J. 

1838.  Flora  Boreali-Americana  .  .  .  v.  2,  London,  p.  177. 
HUNT,  REID. 

1902.  Experiments  with  Zygadenus  venenosus  (poison  camass).     American  Jour- 
nal of  Physiology,  y.  6,  p.  xix. 

IRISH,  P.  H. 

1889.  Plants  poisonous  to  stock.     Oregon  Agricultural  Experiment  Station,  Bulle- 
tin 3,  p.  25-26. 
LLOYD,  J.  U.,  and  LLOYD,  C.  G. 

1887.  Zygadenus  nuttallii:  the  death  camoss  of  the  West.    American  Druggist, 

v.  16,  no.  8,  p.  141. 
MCCARTHY,  GERALD. 

1903.  The  poisonous  plants  of  North  Carolina.     Report,  Commissioner  of  Agricul- 
ture, North  Carolina,  1902,  p.  167. 

MITCHELL,  P.  H.,  and  SMITH,  GEORGE. 

1911.  Physiological  effects  of  alkaloids  of  Zygadenus  intermedius.     American 
Journal  of  Physiology,  v.  28,  no.  6,  p.  318-329,  3  fig. 

NELSON,  S.  B. 

1906.  Feeding  wild  plants  to  sheep.     Washington  Agricultural  Experiment  Sta- 
tion, Bulletin  73,  p.  51-54, 1  fig. 

PARSONS,  MARY  E. 

1904.  The  Wild  Flowers  of  California  .  .  .  illustrated  by  Margaret  W.  Buck.    San 
Francisco,  p.  6-8,  1  fig. 

SLADE,  H.  B. 

1903.  Some  conditions  of  stock  poisoning  in  Idaho.     Idaho  Agricultural  Experi- 
ment Station,  Bulletin  37,  p.  181-183,  1  pi. 

1905.  Some  alkaloids  of  the  death  camas.    American  Journal  of  Pharmacy,  v.  77, 
no.  6,  p.  262-264. 

VEJUX-TYRODE. 

1904.  The  composition  of  Zygadenus  venenosus  and  the  pharmacological  action 
of  its  active  principle.    Journal  of  Medical  Research,  v.  11  (n.  s.  v.  6),  no.  2, 
p.  399-402. 

V/ATSON,  SERENO. 

1880.  Botany.     [Geological  Survey  of  California.]    v.  2,  Cambridge,  Mass.,  p.  183. 

WYETH,  N.  J. 

1899.  Correspondence  and  journals  .  .  .  1831-6  .  .  .     Sources  of  the  History  of 
Oregon,  v.  1,  pt.  3/6.,  p.  225. 


ADDITIONAL  COPIES 

OF  THIS  PUBLICATION  MAY  BE  PROCURED  FROM 
THE  SUPERINTENDENT  OF  DOCUMENTS 
GOVERNMENT  PRINTING  OFFICE 
WASHINGTON,  D.  C 

AT 
15  CENTS  PER  COPY 


Gaylord  Bros. 

Makers 

Syracuse,  N.  V. 
PAT.  JAN.  21 ,1908 


487711 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


